Dvaravati

Definition and chronology

The phase is usually placed in the 1st to 5th centuries,^{[15]: 1, 9} though Murphy restricts it to the 4th and 5th.^{[3]: 368–369} The label was proposed by Andrew Barram and Ian Glover in 2008 and taken up by Murphy, who argues that the sculpture, architecture and urban planning of Dvaravati are the end of a long process rather than its beginning.^{[3]: 367–369} A period of local development must therefore be posited before them, since the older model of a wholesale arrival of Indian culture is no longer held.^[3]: 368 He prefers proto-Dvaravati to late prehistory, which implies societies that have not developed out of Iron Age forms, and to early Dvaravati, which implies a culture already formed.^{[3]: 368–369}

Ian Glover named the interval between the two bodies of evidence the "Pre-Dvāravatī Gap". Late prehistoric finds are rich in iron tools and finely worked hard-stone beads. Dvaravati collections hold little iron and much poorer bead work, but add brick religious architecture and moated enclosures. Glover left open whether this is a break in occupation or simply sites not yet found.^[12]: 16 Radiocarbon dates on brick and plaster at Uthong have since taken occupation back to the fifth or perhaps the fourth century, on which Andrew Barram and Glover argued that the conventional range of about 600–1000 CE should move back some two centuries, the added phase being called Early or Proto-Dvaravati.^{[12]: 85, 99–100}

Murphy also parts from Barram and Glover, who would redate the Dvaravati assemblage as a whole. On his reading the full range of Dvaravati pottery is not yet present in the earlier phase, kendi, a spouted water vessel, do not appear in central Thailand before the 6th century, and some prehistoric forms persist into the 4th and 5th.^{[3]: 379–380} The same argument is applied to the polity. The embassy that reached the Tang court in 638 records the first recognition of Dvaravati rather than its beginning, since a polity had to be self-defining and wealthy enough to mount the journey.^[3]: 391

Archaeological evidence

Archaeological evidence comes from several sites in central and northeastern Thailand. At Chan Sen, the phase dated to about 200–450 or 500 CE, formerly classified as Funan-related, is now considered closer to Dvaravati than to the Mekong delta; the sites around Chan Sen also developed from an unranked settlement pattern in 200 BCE–300 CE to a two-level hierarchy by about the 5th century.^{[3]: 383, 385} At Nakhon Pathom, Hor-Ek was occupied from the 3rd to the 11th centuries, with its earliest phase proposed as pre- or proto-Dvaravati.^[3]: 384 At U Thong, the moat and first Indic contact are placed by the mid-4th century at the latest.^{[3]: 385–386} At Kamphaeng Saen, the first occupation dates to the fifth or sixth century, with the most intensive phase in the seventh before decline and abandonment by the ninth.^{[27]: 337, 341} Phromthin Tai near Lopburi and Kheedkhin in Saraburi show continuity from late prehistory into the Dvaravati period, but no separate proto-Dvaravati phase.^{[3]: 388–389} In the northeast, Mueang Sema [th] has a 4th- to 5th-century phase classified as late prehistoric, while Mueang Fa Daet has a proto-historic phase dated to about the 2nd to 6th centuries.^{[3]: 389–390} At Si Thep, a burial group dates to 240–390 CE, while the circular moat dates to 414–602 and its eastern rectangular extension to 505–681; the excavator notes that it is unknown whether the people buried there were the same as those who laid out the town.^{[28]: 117–121, 124–125}

The region was occupied from at least c. 1000 BCE. Between about 900 and 200 BCE the material record shows growing participation in maritime exchange, with settlement continuing through the Bronze and Iron Ages;^{[15]: 2–4} by the 1st or 2nd century CE contacts extended to South Asia, China and farther west.^{[15]: 3, 4 [29]: 23} Finds at several sites have been linked to exchange networks tied to Funan,^{[15]: 3, 4} though the political relationship remains debated.^[15]: 3 Murphy argues that the ceramics of Nakhon Pathom indicate trade rather than Funanese overlordship, and that material previously classified as Funanese is closer to Dvaravati.^[3]: 385 The late-BCE cemetery at Ban Don Ta Phet [th] in Kanchanaburi provides further evidence of these long-distance networks, with finds including iron tools and weapons, imported beads and bronze vessels, a Sa Huỳnh-type nephrite pendant, a Dong Son bronze situla, and figurines associated with Indian religious traditions.^{[12]: 15–16, 19, 22}

In the eastern plain, Sup Champa (เมืองโบราณซับจำปา) in Lopburi Province points to a complex society by about 500 BCE, though its regional role remains unclear.^{[30]: 49–50} By the 5th or 6th century CE Uthong still held a central position while Nakhon Pathom was growing alongside it.^{[16]: 39–40} From the 6th to the 10th centuries, Nakhon Pathom is regarded as a supra-regional center of the Dvaravati cultural sphere,^{[31]: 8–9 [32]: 55} alongside major centers such as Si Thep.^{[33]: 151–2}

Origin traditions and migration narratives

The Tai Yuan Legend of Singhanavati calls the lower Menam Basin before the Dvaravati period Lava-rāṣṭra (ลวรัฐ; lit. 'land of the Lawa people'),^{[34]: 33 [35]: 60} meeting Yonok around the mouth of the Ping River.^[34]: 37 This fits Gordon Luce’s view that the Lawa once held much of central Thailand as far south as Lopburi, an argument resting on a supposed link between Lavapuri of the seventh-century Lavo Kingdom and the ethnonym Lawa.^[36]

The same text records continuing dealings between Tai Yuan and Lawa or Lua groups from the founding of Yonok,^{[34]: 32, 41–2} the first ruler Singhanavati [th] subduing several existing settlements, some of them implicitly Lawa.^[34]: 32 Marriage followed: the third Yonok king, Achutraraj (พญาอชุตราช), took a Lawa princess of Doi Tung as chief queen,^{[34]: 36–7} and their son succeeded him.^[34]: 49 The Lawa town of Wiang Phang Kham served the Singhanavati kings as their base in the campaign to recover Yonok from Umongkasela in the late 4th century.^{[34]: 73–4}

Late in the Yonok period Chaiyasiri is said to have faced invasion by the Mon kingdom of Thaton, and in 444 CE to have led some 100,000 households south into the upper Chao Phraya basin, founding a settlement at present-day Kamphaeng Phet.^{[34]: 90–3} No relationship has been shown between this narrative and the earliest epigraphic occurrence of the ethnonym syam, in the Funan inscription K.557 of 611 CE.^[37]: 21 From a separate tradition, the Tang Huiyao and the Cefu Yuangui record an independent polity, Duō Miè, small in extent but populous, lying against the western border of Dvaravati's Tou Yuan, which was centred either at Lopburi or at Si Mahosot.^{[38][39]: 20} The migration story also shaped later reconstructions of Tai-speaking movement, which posit two routes, one from the northwest by way of the later Möng Mao^[40]: 5 and one from the northeast by way of Muang Then.^[40]: 3

Western accounts of the Ayutthaya period record that King Phrom of the Singhanavati dynasty, father of Chaiyasiri, was held to be Ayutthaya's first monarch. Jeremias van Vliet, Guy Tachard and Simon de La Loubère report the belief as widespread and reinforced by court tradition under Maha Chakkraphat, Prasat Thong and Narai, which traced the royal line to Phrom.^[41] It has also shaped readings of the Burmese chronicle Hmannan Yazawin, which records that in 1056 the Gywans of Ayoja, or Arawsa, southeast of Thaton,^[42] attacked the Mon centre there.^{[43][44]: 25} George Cœdès identified Ayoja with Ayodhya or Siam;^[45] Francis H. Giles took the Gywans for descendants of the Tai Yuan.^[46]

Rivalry among Dvaravati polities

Rivalry between regional centres such as Nakhon Pathom and Si Thep has been proposed, with later local traditions often read as reflecting it. Support for competition among the largest centres has been drawn from their moats. Eight moated settlements in the central plain were enlarged, five of them either regional centres or their nearest neighbours.^{[31]: 19–20} Nakhon Pathom originally enclosed about 300 ha, close to Suphanburi, before later expanding to 602 ha; Phraek expanded from 81 ha to 315 ha. Mudar suggested that if these expansions were contemporaneous, the three may have been capitals of competing polities, with Nakhon Pathom's near doubling potentially marking the outcome of that competition. The expansions, however, have not been relatively dated.^{[31]: 11, 19–20, 24}

The earliest narratives of conflict appear in versions of the Legend of Nakhon Chai Si and the Legend of Phra Praton Chedi. Siddhijaya is said to have come from Manohana,^{[53]: 11–2} a name identified with Ayojjhapura in the Pali Ratanabimbavaṃsa [th] and Jinakalamali,^{[48]: 3–4} and in turn with Si Thep,^[2] and to have taken power in the Nakhon Pathom region about 590 CE after defeating the preceding ruler.^{[53]: 11–2 [48]: 2} A Dvaravati mission to China in 616 was recorded under Tou-he (投和國), with its ruler named Pu-xie-qi-yao (脯邪乞遙), which has been compared phonetically with Siddhijaya.^[16]: 130 Tradition instead has Kakabhadra holding parts of the region until 641, when his elder son Kalavarnadisharaja succeeded him,^[53]: 12 leading to the proposal that Siddhijaya and Kakabhadra may have been the same person because their supposed territories and dates overlap.^[48]: 4

Later tradition has Brahmins from Nakhon Pathom founding Lopburi, south of Si Thep,^{[53]: 11–4} around 629,^[b] with the city completed in 648 and Kalavarnadisharaja, son of Kakabhadra, as its first ruler.^[54][55] The Northern Chronicle [th] describes his reign as expansive,^[54]: 25 politically reaching Chiang Saen and involving dynastic ties with Tai Yuan rulers.^[48]: 4 It does not describe his dealings with Si Thep, whose 6th- and 7th-century ruling line is attested by the Ban Wang Pai inscription (K.978)^{[56]: 17–9} and later linked by the Jinakalamali to Rajadhiraj,^[2] a king of Ayojjhapura.^{[57]: 97, 125–6} The foundation story conflicts with the Cāmadevivaṃsa, which places Lavo under Navaratna (นพรัตน์) in 647,^[58]: 23 before Kalavarnadisharaja's supposed accession.^[58]: 19 Xuanzang likewise knew Lavo as Luó-wō-guó (罗涡国) by 629,^[59]: 83 while some sources place its foundation as early as 538.^[60]: 34

Authority in the Menam basin appears to have been reordered after the last tribute mission attributed to Dvaravati, the Tou-he kingdom (投和國), in the Zhenguan period (貞觀, 627–649).^[61] Tatsuo Hoshino places a possible shift as early as about 665, when Pú jiā yuè mó, associated with Si Thep, is said to have brought the Si Thep and Nakhon Pathom regions under one authority.^[10]: 54 This did not last. The Jinakalamali later has Anuruddha, ruler of Arimaddanapura, often identified with Nakhon Pathom, campaign against Ayojjhapura or Si Thep and capture its ruler Manohanaraj,^[48]: 4 while the Northern Chronicle has him continue towards Indaprasthanagara in the Phraek region.^{[62]: 88–91}

The tribute sequence had begun in 638 with an embassy arriving without Linyi, through which most South Seas missions then passed; the Cefu Yuangui notes at this first appearance that the state belonged to the Kunlun category. Missions followed in 640, 643 and 649, and in 643 and 647 embassies also came from Tuoheng, which the Jiu Tang shu calls a dependency of Dvaravati.^{[12]: 128–129} In 649 the ruler sent ivory and fire-beads and asked for fine horses, Tuoheng having asked for horses and a bronze bell two years before. Lin Ying and Huang Jiaxin note that such requests were unusual where return gifts were normally silk. The only recorded grant of horses to a South Seas polity under the Tang was two sent to the king of Linyi in 713. They read Dvaravati's willingness to ask as a mark of the standing of a polity by which Chinese sources routinely located others.^{[12]: 128–129}

Late in the 7th century, the Legend of the Arhat has Balidhiraja, eldest son of Kalavarnadisharaja of Lavo and ruler of Sukhothai, marching south, deposing the ruler of the western valley and installing his youngest son Sai Thong Som, while his elder son Balipatijaya took Lavo about 700 CE.^{[48]: 3–5} A ruler called Padumasuriyavamsa then appears at Indaprasthanagara in the central Menam valley^[c] by 757.^[d] Later traditions give him Lavo and Sukhothai and a reach east across the Korat Plateau to Mueang Talung (เมืองตลุง or ตะลุมดอ) in present-day Prakhon Chai,^[65]: 8 and several later Siamese monarchs claimed descent from him.^{[64][51]: 11, 38, 43–4 [66]: 127, 133} A separate Legend of Mueang Phaya Re gives the city's revival to King Sudarśana in the same year.^[67]: 127 An 8th-century terracotta Buddha from Uthong names King Maratha but gives no information on his polity's relation to the other centres.^{[68][69]: 253}

In the early 9th century the Ratanabimbavaṃsa has Adītaraj of Ayojjhapura, identified with Si Thep, besiege Indaprasthanagara after the death of its great ruler.^{[2][70]: 51} The Si Thep line remained a regional power: Bhagadatta is dated to 859 CE by the Śrī Canāśa Inscription (K.949),^[71]: 122 and the line is said to have lasted until 949, when incursions from Angkor ended it.^[72]: 3546 The Nyah Kur people near Si Thep speak an archaic Mon-related language with Khmer loanwords and preserve traditions of ancestors driven into the highlands after Khmer seized their settlement. Their distribution has been linked to the expansion of Angkorian influence in the 10th–11th centuries,^{[73]: 77–80} while Khmer ceramics and Chinese Song dynasty celadon attest activity in the highlands between the 10th and 12th centuries.^[73]: 83

After Adītaraj's campaign, the Northern Chronicle and the Ratanabimbavamsa place Bhūpati of Vajraprākārapura, modern Kamphaeng Phet, on good terms with Ayojjhapura^{[62]: 101 [70]: 52} and Ngoenyang Chiang Rai^[62]: 104 and sending a son to rule Lavo,^[62]: 101 which had been under Indaprasthanagara since Padumasuriyavamsa's reign.^[65]: 8 The Ayutthaya Testimonies also make Vajraprākārapura a foundation of one of Padumasuriyavamsa's descendants.^[51]: 11 A few decades later the Jinakalamali and Cāmadevivaṃsa have Uchitthaka, a cakravartin, lose Lavapura to Sujita of Tambralinga in 927 and then seize Haripuñjaya, ruling there until 930.^[74] Local ruling lines in the upper, central and western regions appear to have lasted into the late 10th and 11th centuries,^{[16]: 262–3} before pressure from Pagan,^{[17]: 41 [20]: 4} Tambralinga,^[75]: 70 Angkor,^[76] Chola^[8]: 143 and Ngoenyang Chiang Saen.^{[62]: 17–8}

Settlement and religious landscape of Khorat Plateau

Dvaravati culture spread into Isan and lowland Laos from the sixth century, with major sites at Mueang Fa Daet in Kalasin Province and Sema [th] in Nakhon Ratchasima Province.^[77][78] The Khorat Plateau and the middle Mekong, east of the core Dvāravatī centres, appear to have developed outside the Dvāravatī political network as a loose landscape of small fortified and moated settlements. From the site inventories of Thiva Supajanya and Srisakra Vallibhotama [fr], Charles F. Keyes argued that local traditions, especially the legend of Phadaeng Nang Ai and the Tamnan Fa Daet Song Yang (ตำนานฟ้าแดดสงยาง), preserve the names of early settlements there.^{[79]: 497–8} Mueang Fa Daet, the first site in northeastern Thailand identified as "Dvāravatī" by H. G. Quaritch Wales,^[79]: 502 is traditionally attributed to the foundation of Chao Fa Ra-ngum in 621 CE.^[80] Keyes cautioned against applying "Dvāravatī", "Mon" or even "Buddhist" uncritically to the plateau, whose traditions instead depict largely autonomous muang, some with subordinate settlements and others independent, alongside Buddhist practice, fertility cults and local spirit beliefs influenced by Hindu deities.^{[79]: 504–5}

The region's sema stones, Buddhist boundary markers, likewise show a local tradition. Narrative carvings from Mueang Fa Daet Song Yang and Ban Nong Chat, generally dated to the 7th–11th centuries and classified as Dvāravatī work, depict jātaka scenes and the life of the Buddha while marking consecrated ground for ordination and other rites.^{[81]: 352–4} Stephen Murphy argues that their use arose locally as a response to the Vinaya requirement for boundary markers, whose form it leaves unspecified.^{[82]: 262–263} Excavated examples occur not only around ordination halls but also stupas, Buddha images and prehistoric rock shelters, with eight to twenty-four stones in some settings.^{[82]: 260, 270, 272–273} Vimoltip Singtuen and colleagues give four to sixteen for directional settings.^[83]: 1 The later standard of eight stones is first prescribed in the Kalyāṇī inscription of 1477–78, contrasting with this earlier variety.^[82]: 267 An earlier theory held that the tradition reached the Kalyāṇī sīmā at Thaton in lower Myanmar through Mon fleeing Angkorian expansion in northeast Thailand. More recent comparison, however, finds substantial differences in form, composition and style between the two corpora and suggests that the lower Myanmar tradition developed independently.^{[81]: 352, 371}

Political developments in the Plateau

Epigraphic and Chinese evidence likewise points to the plateau being divided among many small polities between the 6th and 9th centuries, with several inscriptions naming local rulers or nobles as religious donors. The Sanskrit Phimai Inscription No. 1 (K.1000) names the Buddhist ruler Sauryavarman in the Phimai region;^[84] the Hĭn K‘ôn inscriptions (K.388 and K.389) name the Buddhist noble Nrpendradhiphativarman and his similarly named father;^[85]: 77 and the Don Mueang Toei [th] inscription records King Pravarasena of Sankhapura.^{[86]: 83–4} The Wat Ban Waan inscription names King Srimanya,^{[87][88]: 275} while the Wat Pa Nong Peng inscription names King Śrīmānarājā and describes his reign as a time of political turmoil.^{[87]: 275 [89]} The Don Mueang Toei inscription further gives a genealogy of three kings of Sankhapura, Pravarasena, Kroñcabahu and Dharmasena, and Michel Lorrillard notes that no link has been established between them and the rulers of Cambodia.^{[90]: 198, 213} Together these records attest multiple local polities before Angkorian authority arose to the south.

During roughly the same period, corresponding to the reign of Mahendravarman of Chenla (r. 600–615), parts of the Khorat Plateau may have come under temporary Chenla influence. His victory inscriptions extend across the Mun–Chi basin, from Dong Mueang Aem in present-day Khon Kaen Province to the Phimai region and the mouth of the Mun in Ubon Ratchathani.^[91]: 49 One inscription (K. 969 / P.Ch. 5), from Prasat Khao Chong Sa Chaeng in Ta Phraya, Sa Kaeo, records the digging of the Śaṅkara Taṭāka, extending the pattern south of the Dângrêk range; others place Mahendravarman's campaigns along the Mekong as far as Champasak in southern Laos.^[29]: 50 These inscriptions were long taken as evidence of Chenla administering conquered territory through vassals. Because they record victories without demonstrating lasting control, however, Michael Vickery argued that they do not establish direct Chenla authority beyond the Dongrek Mountains.^{[92]: 462 [85]: 76 [93]: 79} He instead regarded the campaigns as temporary expeditions with limited political effect,^[29]: 50 after which regional inscriptions name no ruler from the Tonlé Sap basin for several centuries.^[91]: 103

A firmer connection with Chenla may date from the reign of Isanavarman I (r. 616–637), Chinese records placing a polity called Bhīmapura under him which some identify with Vimayapura, Phimai.^[7]: 49 Others read Chinese accounts of Zhu Jiang and Can Ban as allies of Chenla by marriage to mean that polities of the central plateau and upper Pa Sak basin formed dynastic ties with his court.^[94] Much of the plateau appears to have lain where the Chenla and Dvaravati spheres overlapped, while its northeast, covering present-day Nakhon Phanom and Sakon Nakhon and Khammouane in Laos, appears in early 7th-century Chinese sources as the two districts of Changzhou Prefecture (長州 or 裳州).^{[10]: 49–51} Hoshino places the early Tai polities of Gǔ Láng Dòng (古郎洞)^[10]: 49 and Jūn Nà Lú (君那盧)^{[10]: 60–1} in this region. Changzhou, however, disappears from the Chinese record after the emergence of Wen Dan, whose relationship to it remains unclear.

From the mid-7th century, Chinese sources suggest weakening Chenla influence, with several polities appearing independently. Zhān Bó, often placed at Champasri,^[10]: 38 sent tribute to China in 657 and may have formed from the merger of Zhān Guo (瞻國) and Bó Guo (博國).^{[10]: 47–8} Pó Àn (婆岸), recorded in the New Book of Tang, has been tentatively placed around modern Phon District.^[10]: 30 Hoshino interpreted Zhān Bó, Pó Àn and several states of the Menam valley and Cham coast as a trans-Mekong trade confederation^[10]: 42 distinct from the Dvaravati polities of the coast.^[10]: 30 After the reign of Jayavarman I (r. 657–681), Wen Dan may have separated from Chenla between 681^[7]: 123 and 707,^[7]: 59 before sending its first recorded tributary mission to China in 717.^{[10]: 41, 47} Cœdès identified Wen Dan with Mūladeśa,^[95]: 87 a toponym attested in the K.187 inscription.^[96]: 90 Chinese records further state that in 755 Wen Dan assisted a native Nghean lord in wars against the Chinese governor at Jiaozhou, after which the lord enthroned himself as Hei-ti (lit. 'Black Emperor').^{[citation needed]} Woodward likewise suggests that Wen Dan's influence extended beyond the Khorat Plateau into the Si Thep and northern Tonlé Sap regions, where pre-Angkorian Buddhist and architectural remains have been interpreted as reflecting connections with the Wen Dan cultural sphere.^{[95]: 87–94}

References to the plateau grow rarer from the 9th century, with Wen Dan's last recorded mission to China in 799. The plateau and much of present-day Laos are generally held to have entered the "Java Period" as Angkor rose in the Tonlé Sap basin.^{[10]: 61–2 [95]: 93} Since Java also appears in Angkorian foundation narratives,^[21]: 56 its referent is debated: the island of Java, Cham-related mainland polities, or other maritime powers of the region.^{[10]: 61–2 [21]: 56 [97]: 71–5} Woodward adds the northern Malay Peninsula, a principality far up the Mekong, and Wen Dan itself, while noting that the tradition has also been treated as a late myth.^[95]: 93 Inscriptions of Jayavarman VII (r. 1181–1218) further complicate the issue by naming a "King of Yavana" alongside a "King of Java" and two kings of Champa, indicating distinct but unidentified entities.^[97]: 62

Hunter Watson divides Thailand's Old Mon inscriptions into three phases, with the plateau forming the second, dating to about the eighth to tenth centuries and using a post-Pallava script. Most are short texts on sema stones recording meritorious acts and donors' names. They come from Chaiyaphum, Khon Kaen, Udon Thani, Sakon Nakhon, more recently Phetchabun, and Kalasin, including one dated to 771 CE, with another group known from Vientiane in Laos. Watson cautions that their distribution does not by itself define Dvaravati's extent, since sites bearing such inscriptions need not have been affiliated with it.^{[12]: 87–88, 92–93} Skilling likewise suggests that the unusually large stone images from Wat Chanthuek and Sung Noen indicate an independent centre of power and wealth around old Khorat.^[12]: 81

The reach of these religious traditions into small inland polities is also illustrated by a hoard of silver and gold found in 2008 at Nong Hua Thong in Savannakhet, Laos, at a fortified settlement on the Xe Bang Fai. Dating broadly to the eighth to tenth centuries, it includes silver vessels in late Tang style, a silver Garuda, and a repoussé plaque of a seated ascetic tentatively identified as Kubera. The hoard is held by the provincial government and closed to study.^{[12]: 56, 59–60}

Dvaravati–Chenla relations

Dvaravati polities of the Chao Phraya basin have been held to have maintained dynastic ties with those of the Tonlé Sap basin and the Mekong Delta since the Funan period.^[98]: 43 Cœdès identified Chakravartin, the father of Prathivindravarman of Si Thep in the Wang Pai Inscription (K.978), with Rudravarman, the last ruler of Funan's Candravaṃśa line.^{[99]: 156–8} Claude Jacques instead identified him with Mahārājādhirāja Śrī Devanika, whom the early 5th-century Devanika Inscription (K.365) describes as coming from a distant land; on this reading, Devanika ruled from Si Thep and sent princes to settlements along the trans-Mekong trade route, including Vat Phou, whose ruling line was later associated with Chenla.^{[100]: 68–9} Zakharova disputes the identification.^[101]: 143

Cœdès and Jacques initially dated the Wang Pai Inscription to the mid-6th century and identified its Bhavavarman with Bhavavarman I of Chenla, but Jacques later read it as referring to a local ruler of Si Thep.^{[98]: 37–9} Kangwon Katchima instead dates the inscription after 637 on epigraphic grounds, identifying its Bhavavarman as Bhavavarman II or another local ruler,^{[56]: 17–9} whose authority may have reached no further than south of the Dângrêk Mountains.^[98]: 41 Meanwhile, Anurak Depimai argues that he cannot be Bhavavarman II because the Wat Kud Tae Inscription makes Bhavavarman II a son of Isanavarman I.^{[98]: 40–2}

Under Isanavarman I of Chenla (r. 616–637), Chenla sought to extend its influence into the Menam Basin, particularly toward Tou Yuan,^[94][102] whose main centre has been proposed as either modern Lopburi^{[10]: 36, 54} or Si Mahosot.^[103] A Chao Phraya valley fable links the conflict to a marriage between a Chenla princess and a Dvaravati ruler.^[104] Michael Vickery separately proposed that Harshavarman, who claimed descent from Isanavarman and later ruled Uthong, headed a branch of the Chenla royal house centred in central or eastern Thailand; the Copper Plate Inscription records the descent but not the proposed marriage.^[29]: 51 Karen Mudar instead interpreted the plate in light of the settlement hierarchy: U Thong's 73.3 ha moated area was a district centre, which she suggested may represent lost autonomy rather than a royal court.^{[31]: 8, 20, 25} Revire cautions against dating the plate from a single letter form. The short medial vertical of its ka is often taken as a marker of post-Pallava script and thus a date after the seventh or eighth century, but the same form occurs in dated seventh-century inscriptions from southern Cambodia, including K. 79 (644 CE), K. 50 and K. 582 (667 CE). He therefore treats it as a possible regional variety and notes that inscribed copper sheets, common in India and Indonesia but unknown in Cambodia, may support the possibility that the plate reached U Thong from elsewhere.^[22]: 410

Under Isanavarman I, Chenla also established marriage ties with Champa^{[98]: 44–6} and Dvaravati-sphere polities such as Zhu Jiang and Can Ban.^[105] The western Menam basin likewise shows artistic influences from both Chenla and Champa.^{[29]: 49–53 [98]: 44–6} Dvaravati also formed a dynastic connection with a polity in the upper Mun Basin through the marriage of a princess to its ruler, recorded in the Wat Chanthuek Inscription (K.1009);^[98]: 48 Skilling suggested, without deciding, that this polity may have been Cānāśa.^{[12]: 66, 81}

After Isanavarman I's death, his successor Bhavavarman II (r. 639–657) appears in the Wat Kud Tae Inscription at war with Dvaravati Sambuka, commonly identified with modern Nakhon Pathom.^{[106]: 24–25, 30 [107][108]: 10} Chaowanee Lekkla, however, gives Śambūka only as the name of his adversary's town and does not locate it.^[109]: 101 Tatsuo Hoshino argued that the conflict involved several polities, including Qiān Zhī Fú (later Gē Luó Shě Fēn), Xiū Luó Fēn and Gān Bì.^{[10]: 46, 54–55} Tou Yuan, previously targeted by Chenla expansion, was recorded in 647 as a vassal of Dvaravati,^[7]: 269 while Kalavarnadisharaja (r. 641–700) of Dvaravati Nakhon Pathom founded or refounded the Lavo Kingdom in 648.^[10]: 54

Jyesthapura, identified with Mueang Phai and the area around Prasat Kao Noi,^[108]: 10 served as the seat of Bhavavarman II from 637 to 639 before he moved toward the lower Tonlé Sap region.^[98]: 47 The Khao Noi inscription (K.506), dated 637, names Isvarakumara as svāmi of Jyesthapura, while the Wat Kud Tae inscription (K.1150) names Sivadatta, a son of Isanavarman I and elder brother of Bhavavarman II, in the same office.^{[29]: 50–1} During this period, Dvaravati polities in the western Menam Basin extended their influence eastward to the same frontier zone around Mueang Phai and Prasat Khao Noi.^[108]: 10 This period of close contact between Dvaravati and Chenla, involving both alliances and conflict, also coincides with pre-Angkorian references to syam as a toponym or ethnonym in K.557 (611 CE), K.79 (639), K.127 (683), K.154 (685) and K.904 (713), including references to enslaved persons and a landholding official.^{[110]: 21, 69, 89, 123 [111]: 54} These references disappear after Chenla fragmented in the early 8th century.

Dvaravati and Wen Dan

In the same period, the region northwest of the Tonlé Sap, south of the Dângrêk Mountains and around present-day Battambang Province, is described as having divided into four polities that sent their own embassies to China after breaking away from Chenla.^[98]: 48 By the 720s, the region appears to have fallen within the sphere of Wen Dan, a polity associated with Dvaravati. Two groups of Buddhist boundary stones (Bai sema) on Mount Kulen were initially proposed as 8th-century foundations of Wen Dan, but the argument was later withdrawn as premature because the stones cannot be dated closely enough to determine whether they predate or postdate Jayavarman II's accession in 802.^[95]: 88 The case instead rests mainly on the scarcity of inscriptions and the apparent cessation of monumental construction in the Angkor region from about the 720s.^[95]: 90 On this basis, Hiram W. Woodward proposed that the northern Tonlé Sap region was no longer under Lower Chenla but within the sphere of Wen Dan,^{[95]: 87–8, 91} which maintained close relations with,^{[95]: 91–2} or exercised authority over, Si Thep.^[95]: 94 Population movements from the region toward Si Thep in the early 8th century have likewise been associated with Wen Dan.^[95]: 91

The Tonlé Sap polities were reunified in the early 9th century, when their principal centre shifted north toward the Angkor region.^[112] Jayavarman II (r. 780–850), a ruler of Lower Chenla later regarded as the founder of the Angkorian monarchy, is recorded as renewing relations with the Mun–Chi basins, where the former ally Zhu Jiang lay, and meeting Dvaravati Si Thep in the Menam–Pa Sak valleys. Woodward further proposed that Jayavarman II defeated Wen Dan, after which the remaining Dvaravati-associated region in the Chi valley entered the Javā era.^[95]: 93 Archaeological and textual evidence, however, suggests that Dvaravati's political predominance was already declining by the early 8th century.^[53]: 60

Angkorian expansion into former Dvaravati territories resumed in the 10th century. Under Rajendravarman II (r. 944–968), Angkor took Si Thep in 946,^[e][113] after which the city declined and was abandoned by about the 13th century, as Sukhothai and Ayutthaya rose.^[114] Lavapura of Lavo came under Angkorian influence from the 10th century^[13]: 23 and under Angkorian authority in 1005, under Suryavarman I (r. 1002–1050).^[19] He also recovered polities lost to Dvaravati since the 8th century, including Jyesthapura in present-day Sa Kaeo Province and Candhrapura in Chanthaburi Province, and took the former Dvaravati vassal Avadhyapura in Prachin Buri Province.^{[108]: 10–4}

Dvaravati–Champa relations

Contact between the Dvāravatī sphere and Champa is attested chiefly through art and architecture. Varis Domethong divides it into two phases with different geographies.^[115]: 16 Between roughly the sixth and ninth centuries, the Thai material clusters in the Tha Chin and Mae Klong basins, with U Thong, ancient Nakhon Pathom and Khu Bua as the main sites; Si Mahosot is the eastern outlier. From about the ninth century, the western evidence thins and the eastern evidence disappears, while comparable material appears in the northeast at Mueang Fa Daet and Phra That Phanom. On the Cham side, the distribution likewise contracts from a broad area to the Quảng Nam sites of Dong Duong, Tra Kieu and My Son.^{[115]: 18–19} Domethong considers this distribution preliminary because access to Cham material in Vietnam is restricted.^[115]: 18

The earlier phase is represented mainly by Brahmanical material. A kośa recorded on the U Thong copper plate corresponds to a rite attested at My Son in 687, while Dvāravatī figures of dancers and musicians have been compared with the My Son E1 pedestal.^[115]: 22

The later phase is Buddhist and concentrated in the northeast. At Phra That Phanom, Domethong compares the earliest building phase with the Dong Duong style of Champa and dates it to the early tenth century, following the transfer of the Cham capital to Indrapura in 875. He also points to Cham-style brickwork and reliefs comparable to those at Dong Duong.^{[115]: 23–25, 34} At Mueang Fa Daet, similarities occur in the sema stones and a lion sculpture. Murphy has argued that one distinctive seated figure type occurs in northeastern Thailand and central Champa, suggesting movement of craftsmen between the two regions.^{[115]: 26–27} The Fa Daet lion also follows a type known from Tra Kieu, though Domethong considers it a local interpretation.^{[115]: 25–26, 32}

Domethong interprets the shift as reflecting political and religious change in Champa after 875, but not Cham political control in northeastern Thailand.^{[115]: 29, 32} He follows Phasook Indrawooth in treating Fa Daet Song Yang as an independent polity and the Cham material there as evidence of cultural relations between neighbouring centres.^[115]: 31

Si Thep dominance

After Chenla fragmented in the early 8th century, Si Thep emerged as the principal regional power in the Menam basin. Chinese records place a polity called Qian Zhi Fu (千支弗)^[116] at Si Thep in the eastern-central plain, which sent its first tribute to the Tang court about 656–661 under Emperor Gaozong of Tang.^{[10]: 30, 32} The same passage names Duō Mó Cháng as its northern neighbour; Tatsuo Hoshino places this polity in the river country of present-day northern Thailand, later the Lan Na sphere, placing Qiān Zhī Fú at the northern edge of the upper Menam basin.^{[10]: 30–4, 60}

By the 8th century, Chinese sources also mention Gē Luó Shě Fēn (歌羅舍分), which they place west of Dvaravati.^{[10]: 38–9} Hoshino tentatively identified it with Qiān Zhī Fú, partly through its phonological resemblance to Jiā Luó Shě Fú (迦逻舍佛), which he places at Si Thep with Mueang Sema [de] as a subordinate centre.^{[10]: 32–4} On this reading, Si Thep's sphere extended across much of the lower Chao Phraya valley, including the former Dvaravati centre at Nakhon Pathom, while Lavo remained within the wider Dvaravati network.^{[10]: 38–9} Hoshino further read Qiān Zhī Fú as an early Siamese polity in the trans-Mekong trade between Champa and the Menam basin,^[10]: 54 and linked its name tentatively to the later xiān (暹), the term used in Chinese and Đại Việt sources for Siamese polities of the lower basin.^{[117]: 37–9}

Hiram Woodward reaches a comparable picture from art history, but from a different premise: he places Si Thep itself within Wen Dan. A Si Thep strong enough to dominate the 8th century, he suggests, may have controlled not only Lopburi but also Nakhon Pathom, U Thong and Khu Bua, implying a possible division of Central Dvaravati into pre- and post-Wen Dan phases. He presents this only as a possibility, noting that the Dvaravati features at Si Thep might instead have resulted from the peaceful movement of monks before Wen Dan's rise.^[95]: 93 Excavation places the construction of Khao Khlang Nok in roughly the same period: bricks from its north and east faces gave thermoluminescence dates of 720–848 and 821–875. The monument, located two kilometres outside the town wall, measures 64 m square and 20 m high and has four subsidiary stūpas on its axes and a prepared setting for a dharmacakra.^{[28]: 115–117, 126, 128} Woodward reserves judgement on Hoshino's identification of the other Chinese toponyms with Si Thep, arguing that the evidence requires further review by specialists in the Chinese sources.^[95]: 92

The proposed expansion of Si Thep's sphere also overlaps with gaps in the later dynastic traditions of the Menam basin. The tradition names Sai Thong Som at Nakhon Pathom and his brother Balipatijaya at Lavo as the last rulers of their line, without naming successors.^{[48]: 3–5} The later ruler known from an inscription is Nāyaka Ārjava, identified by K.577 at Lopburi, dated to the 8th or 9th century, as a son of the king of Sambuka, a name several scholars have associated with Nakhon Pathom.^{[118] [106]} The tradition likewise records no successor to Balidhiraja at Sukhothai,^{[48]: 3–5} and some local scholars have interpreted this as evidence that the city was abandoned.^[75]: 8 Hoshino instead places the area within Qiān Zhī Fú, extending northward to the mountain range.^{[10]: 31–4, 60} These gaps fall within the period in which Si Thep has been proposed to have expanded across the Menam basin, although no study has explicitly linked the two.

By the 9th century, Indaprasthanagara, between Nakhon Pathom and Si Thep, entered a period of instability marked by rapid succession. Its chronicle describes a major flood followed by an attack from Ayojjhapura,^{[119]: 94 [70]: 51} which some scholars identify with Si Thep,^[2] after which much of the population dispersed.^{[119]: 94 [70]: 51} Epigraphic evidence nevertheless indicates continued political activity around Si Thep through the 9th and early 10th centuries, with the Śrī Canāśa Inscription (K.949) recording Bhagadatta and his successors from 859 CE.^[71]: 122 Si Thep's regional dominance may have ended with its conquest by Angkor in 946.^[72]: 3546

Economic change and regional shifts

Some scholars date this phase to the 9th and 10th centuries,^[15]: 3 while others extend the Dvaravati cultural horizon into the 11th.^[15]: 6 Economic conditions in the western Menam valley changed,^[15]: 9 alongside continued trade with Tang China through Maritime Silk Road routes.^[15]: 9 Surveys around Uthong indicate low population density during this phase^[15]: 4 and abandonment by the 12th century,^[15]: 3 although trade between Mueang Uthong and the Tang continued in the 9th and 10th centuries.^[15]: 5

The regional balance also shifted as Tambralinga expanded into the lower Menam basin in the early 10th century. Nakhon Pathom, identified with Mevilimbangam, prospered through maritime trade during the rise of Srivijaya despite limited political influence,^[53]: 60 while local traditions referred to the city as Śrīvijaya.^[121]: 25 Lavo, meanwhile, emerged as a regional centre under Angkorian influence from the 11th century.^{[16]: 262–3 [122]: 46}

After Tambralinga briefly took Lavo in 927,^[74][f] and Angkor annexed Si Thep in 949,^[72]: 3546 several Dvaravati centres are described as coming under new rulers or losing their previous position. The Northern Chronicle [th] places the Sukhothai region under Haripuñjaya house in the 950s,^{[123]: 6–10 [62]: 8–10} while the Yonok Chronicle [th] records an attack on Suphannaphum in the 930s, after which its two princes fled north into Haripuñjaya.^[119]: 191 Tambralinga campaigns launched from Lavo against Haripuñjaya likewise failed.^[124] In the same period, the Ayutthaya Testimonies records Sudhammaraja moving the centre of an early Siamese polity from the central Menam valley to Phitsanulok in 937.^[51]: 37

By the mid-10th century, Lavo is said to have come under the authority of Sindhob Amarin at Indaprasthanagara, a transition associated with the tradition of Sricandradhipati, described as a commoner from Lavo who became ruler of Sukhothai in 959.^{[62]: 27–9} Later in the same century, Ipoia Sanne Thora Thesma Teperat is said to have moved his seat from Indaprasthanagara to Lavo's Lavapura.

Lavo under Angkor and its reversal

By circa 1001–1005, Lavo had fallen under Angkorian authority during the reign of Suryavarman I,^[125][19] prompting the Siamese monarch Visnuraja at Phitsanulok to relocate southwestward to Phetchaburi.^[51]: 38 The main evidence cited for the campaign is the Khmer inscription K.1198/Ka.18 of 1014, now in the National Museum of Cambodia, which records Lakṣmīpativarman, a general appointed by Suryavarman I to govern Rāmanya, and describes Lavapura as having become overgrown with jungle before its western districts were restored and repopulated.

U-tain Wongsathit, Kangvol Katshima and Chatupohn Khotkanok interpret the inscription as recording a campaign from Angkor through Phanom Rung and Phanom Wan to Lavapura, where a rebellion by two local families was suppressed in 1011. They date the conquest to 1011–1014 and regard the inscription as the first explicit epigraphic evidence of Dvaravati being conquered by a Khmer army.^{[12]: 137, 139–141} Walailak Songsiri disputes this interpretation. She argues that identifying Rāmanya with the Mon is problematic: the earliest attested Mon form, rmeñ, appears only in an inscription of Kyansittha of Pagan dated 1102, while the Middle Mon rman was probably derived from Pali through Haripuñjaya; the ramañ in the pre-Angkorian Prasat Bassac inscription (K.71) is a slave's name.^[126]: 3 She also notes that the inscription calls the region Madhyadeśa and that Lakṣmīpativarman's family came from the Mekong basin. In addition, inscriptions at Lavo about a decade later record accommodation between Brahmanical and Mahayana practices rather than a city left deserted by war, while no Angkorian inscription from the period records a western campaign on the scale of the wars with Champa.^{[126]: 2–3} K.1198/Ka.18 was found at the Chong Chom–O Smach pass through the Dangrek, between present-day Kap Choeng in Surin and Samraong district in Oddar Meanchey. Walailak considers the findspot relevant to her interpretation of the inscription.^[126]: 2

In 1052, the Angkorian ruler at Lavo was defeated by a king of Haripuñjaya, who installed his younger brother Chandrachota as the new ruler;^[127][128] shortly afterwards, the Siamese ruler Srisimha returned from Phetchaburi to the central Menam valley.^[51]: 40 The Burmese chronicle Hmannan Yazawin records that in 1056 the Gywan warriors — described as descendants of the Thai Yuan^[46] and located by the chronicle in a southeastern land called Ayoja^[42] — marched against the Thaton kingdom, then in the process of annexation by Pagan, an episode corroborated by Burmese inscriptions from the Arakan Pagoda in Mandalay.^[43] The chronicles of Thaton likewise mention an attack by the Krom, with both ethnonyms likely referring to the Khom people.^[44]: 25 Cœdès proposed that Ayoja corresponds to Ayudhya or Siam.^[45]

Mahidharapura line and the Menam polities

Events at Angkor also reshaped the northern Menam region. The Mahidharapura line of the Phimai region lost Angkor and Preah Vihear to Suryavarman I around 1010 in a succession struggle, while the rival claimant Jayavirahvarman withdrew toward Phimai, where an inscription of 1008 records his donation to the god Vimāya after the loss of Angkor.^{[12]: 138–139 [129][130]: 120–1} The loss of authority by the Mahidharapura elite has been interpreted by some scholars as involving their displacement into what is now upper northeastern Thailand.^[131] The line reappears in the north later in the century, when Pha Mueang, lord of Mueang Rad, received a Khmer title, regalia sword and princess in marriage from the ruler at Angkor.^[13]: 35 The princess, Sukhara Mahadevi [km], is associated with the court of Jayavarman VII, and the marriage has been interpreted as strengthening the role of the Tai Lueang (ไทเลือง) house.^[132]

These developments coincided with traditions of Tai movements and alliances in the upper Menam valley. The Northern Chronicle describes a coalition of Tai Yuan mueang under Śrīdharmatripiṭaka (ศรีธรรมไตรปิฎก) of Ngoenyang Chiang Saen moving south during the reign of Suvacanaraja of Chaliang, beginning around the 1050s. The conflict was settled by marriage, with Suvacanaraja giving his only daughter to Śrīdharmatripiṭaka,^{[62]: 17–8} who is also credited with rebuilding Phitsanulok.^{[62]: 19–24} The same tradition places Śrīdharmatripiṭaka at Phitsanulok from 1106 until his death,^[133] although scholars generally date these events later than the chronicle's stated date of about 1500 BE (957/58 CE).^[62]: 23 In the lower basin, the death of Narai of Ayodhya in 1087 without an heir is said to have led to a two-year succession war among nine royal houses, won by Phra Chao Luang.^{[62]: 40–2 [128]}

The union of the Śrīdharmatripiṭaka and Suvacanaraja houses is said to have produced two princes, with the elder, Kesariraja, becoming ruler of Lavo^[62]: 18 around 1106.^[133] A son of Kesariraja, Duangkrian Krishnaraja (ดวงเกรียนกฤษณะราช), is said to have married an Ayodhya princess, a daughter of Phra Chao Luang (r. 1089–1111), linking the northern houses with the Siamese polities farther downstream.^{[62]: 23–4 [123]: 104}

Phitsanulok provides a geographical link between these traditions and the later history of the upper Menam. The Northern Chronicle places Śrīdharmatripiṭaka at Phitsanulok from 1106 until his death,^[133] while inscriptional evidence has been interpreted as linking the area to a Tai Lueang house traced to Sri Naw Nam Thum. From the late 12th to the mid-14th century, this house is said to have held the upper eastern Menam, particularly the lower Nan River basin around Uttaradit and Phitsanulok. The line then passed the territory to the Xiān house of Si Inthrathit under Maha Thammaracha I.^[134]: 9 The latter is said to have moved the capital from Sukhothai to Phitsanulok in 1349.

Urangkhathat and the middle Mekong network

The middle Mekong and Khorat Plateau formed a transitional zone between the Dvāravatī sphere and the pre-Angkorian polities. Wen Dan last sent an embassy to the Tang court in 799, after which it disappears from the written record. Archaeological evidence indicates that the middle Mekong came increasingly within the Angkorian sphere from about the 9th century, while later local traditions provide much of the surviving evidence for the region's political geography.

The Urangkhathat (ตำนานอุรังคธาตุ), the foundation legend of Phra That Phanom, preserves a network of interconnected polities rather than a unified kingdom.^[135] Its political geography has been dated to the 10th century and later, chiefly from the earliest architectural phase of Phra That Phanom, which predates later Lao and Isan renovations.^[121]: 18 Its principal centres include Sri Kotabun (ศรีโคตรบอง), Nong Han Luang (หนองหานหลวง), identified with Sakon Nakhon, and Nong Han Noi (หนองหานน้อย), or Khun Khom Nakhon (ขุนขอมนคร), in the Kumphawapi area of Udon Thani. The tradition also connects them with Candrapuri (Vientiane), Sri Sattanak (Luang Prabang), Chulani Phromathat, associated with the Cham polity at modern Huế, and Indaprasthanagara, whose location remains disputed.^[135]

Within this network, the Urangkhathat gives particular prominence to Saket Nakhon Roi Et Pratu (สาเกตุนครร้อยเอ็ดประตู; lit. 'Saket, city of a hundred-and-one gates'), which it places on a level with Yothika (โยธิกา), Kurunta (กุรุนทะ), or Ayodhya in the Menam Valley.^[135] Its ruler, Phaya Suriyawongsa Sitthidet, is described as exercising ritual overlordship over subordinate polities whose rulers presented gold and silver flowers each year. The name Roi Et, meaning a hundred and one, is generally understood as a symbol of pre-eminence rather than a literal number of dependent towns, while Saket, an Indian toponym associated with Ayodhya in Hindu, Buddhist and Jain traditions, appears to function as borrowed sacred geography legitimising regional kingship rather than evidence of direct contact with India.^[136]

Nong Han and the Chi–Mun basins

A more localized account of political organization on the northern Khorat Plateau appears in the legend of Phadaeng Nang Ai, centred on the Nong Han–Sakon Nakhon area also named in the Urangkhathat. It portrays a ruler known as Phaya Khom (พญาขอม) as king of Muang Nong Han. Charles F. Keyes identified this polity with present-day Nong Han in Udon Thani Province, although the earliest Lao accounts associate the legend with the Sakon Nakhon site. Both sites have rectangular, Angkorian-style moated plans. In these accounts, Phaya Khom placed his sons and grandsons over a network of muang extending across the northern and central Khorat Plateau, including Muang Chiang Hian–Ban Iat (เมืองเชียงเหียน–บ้านเอียด), Muang Si Kaeo–Phak Waen (เมืองสีแก้ว–ผักแว่น), Muang Hong–Muang Thong (เมืองหงส์–เมืองทอง), and Muang Pheng (เมืองแพง).^{[79]: 498–503} Some versions also include Muang Fa Daet in this network.^[137] The story ends with Muang Nong Han sinking beneath the water.^[79]: 500 This motif has been taken to favour Sakon Nakhon, whose old moated city includes a low-lying northern sector subject to seasonal flooding, while the Urangkhathat similarly places the submersion of Khun Khom Nakhon at Nong Han Noi.^[135] Regional rulers in these traditions are also consistently called Phaya Khom, an epithet associated with the Angkorian sphere, and the traditions preserve relationships among the principal muang of the middle Mekong and Khorat Plateau.^{[131][79]: 503}

The southern basin followed a different course. In the late pre-Angkorian period, the area, where Dvaravati culture spread without a strong central authority, formed part of the loosely organised and generally identified as Canasapura emerged around Mueang Sema [fr] in present-day Nakhon Ratchasima.^[138] From the 9th century, the region came increasingly within the Angkorian sphere. Angkorian influence overlaid rather than immediately replaced the existing Dvāravatī landscape, producing a mixed Dvāravatī and Khmer material culture, while inscriptions from Mueang Sema still placed the polity outside "Kambujadesa", Angkor proper.^[138] Integration continued through the 10th and 11th centuries, including under Jayavarman V (r. 968–1001), whose court brahmin Yajñavaraha founded religious establishments at Mueang Sema, and Suryavarman I (r. 1002–1050), when Prasat Preah Vihear was built on the Dângrêk escarpment above the region.^[138] By contrast with the network of semi-autonomous centres preserved in middle Mekong traditions, the southern Mun basin was progressively incorporated into the Angkorian state.^[139][140]

Pagan expansion and final decline

The 1056 Gywan incursion has been taken to mark Anawrahta of the Pagan Kingdom extending his authority into the lower Menam basin. Nakhon Pathom may have been destroyed about 1058^{[17]: 95, 105} and Lavo submitted.^{[141]: 18–9 [62]: 37–9} Several urban centres appear to have been destroyed,^{[20]: 4 [17]: 41} while Nakhon Pathom lost most of its population between the 11th and 12th centuries.^{[17]: 63, 167–8} It had already been weakened by the wars between Haripuñjaya and Lavo in the early 10th century^[17]: 105 and was reportedly raided in the late 1020s or early 1030s during the Southeast Asian campaign of the Chola ruler Rajendra I.^[g]

The Northern Chronicle records the Pagan noble Kar Tayy exercising political authority over the Suphannaphum–Uthong region^[62]: 60 from about 1081 to 1121,^{[144]: 43–4} after which Mueang Uthong was abandoned^[15]: 3 and Suphannaphum appears to have been left without a ruler.^[62]: 61 The chronicle also recounts a Pagan invasion of the newly refounded Ayodhya in 1087. Although Ayodhya prevailed, its ruler, Narai I, died that year.^{[62]: 40–2 [128]}

Around the same period, the Legend of Nakhon Si Thammarat [th] describes Sri Dharmasokaraja I as a ruler from Pagan's Hanthawaddy who governed Indaprasthanagara–Lavo in the east-central Menam valley until about 1117, before moving south to Nakhon Si Thammarat.^{[145]: 36–43} The Xiān royal seat likewise shifted northward under Surindraraja, from Phraek to Chai Nat.^{[51]: 41 [h]} Sri Dharmasokaraja I is also identified with Narapati (พญานรบดี),^[147]: 7 a name found in the Jinakalamali, where Narapati is identified as king of Suphannaphum and father of King Āditya (อาทิตย์) of Chanabotwichet (ชนบทวิเชต), probably modern Mueang Tak, in Syampradesh. The Jinakalamali treats Chanabotwichet as a separate country from Suphannaphum, while linking this ruling line to northern Thai polities through Buddhist connections.^[57]: 146

Taken together, these accounts suggest roughly a century of Pagan penetration into the Menam valley, consistent with the early 13th-century Zhu Fan Zhi, which places Pagan on Chenla's western border.^[59]: 99 After Sri Dharmasokaraja I moved south, Angkor recovered Lavo^[145]: 39 and again expanded into the Menam basin.^{[53]: 170–88} This may correspond to the Banteay Chhmar Inscription, in which Jayavarman VII and his son march against an invasion from the west, and the Prasat Tor Inscription, in which he defeats the monarch of the west in 1189/90 or 1195/96.^[44]: 24 Baker and Pasuk read the Banteay Chhmar text more narrowly: it records Jayavarman VII and his son resisting an army from the west without specifying how far west it came, and therefore does not establish the extent of Angkorian expansion.^[13]: 22

Regional transformation

The 12th and 13th centuries saw fragmentation and competition among new centres in the Menam and Mae Klong River basins, several of which became the attested Siamese states of Phrip Phri, Suphannaphum, Suvarnapura, Sukhothai and Ayutthaya. Older centres declined. Si Thep remained under Angkorian authority^{[21]: 303, 308–309} but declined politically and economically^[148] and is generally held to have been abandoned by about the 13th century.^[114] Nakhon Pathom and Khu Bua also appear to have lost population,^{[53]: 190–3 [122]: 55–6} while power shifted towards the Mae Klong basin, including modern Ratchaburi and Mueang Sa Kosi Narai (เมืองสระโกสินารายณ์).^{[53]: 186–9} These have been identified with Jaya Rajapuri and Sambukapattana in the Preah Khan Inscription (K.904),^[122]: 53 and both show clear Angkorian cultural influence,^{[53]: 190–3 [122]: 47} as does nearby Pong Tuek [de].^[149]

The principal western Menam centre appears to have been Mueang Sing, while the eastern plain was centred on Lopburi, which alternated between Angkorian control and local autonomy.^[150] The Preah Khan Inscription names them Sri Jayasimhapuri and Lavodayapura.^[122]: 53 The extent of Angkorian authority over the Menam valleys under Jayavarman VII remains debated. The hospitals (arogyasala) and fire houses (vahnigrha) along the roads from Angkor reach no further west than Prachin Buri, while the dispatch of Jayabuddhamahanatha to at least six Menam polities may instead represent cultural diplomacy.^[13]: 24 Baker and Pasuk find little evidence of direct administration. Angkorian records describe campaigns east but only one ambiguous western one, the Banteay Chhmar text; the Menam plain lacks the temple-endowment inscriptions and Khmer official titles usual in Angkorian provinces; and no resource transfers from the plain are documented. They conclude that Angkorian influence was uneven, while Srisakra Vallibhotama holds that local rulers adopted Angkorian political and ritual forms selectively, without necessarily coming under direct administration.^{[13]: 22–3}

Mueang Sing illustrates this selective interaction. Its architecture closely follows the Bayon style of Jayavarman VII's reign,^{[151]: 2 [152]} but archaeologists suggest that the master craftsmen may have come from Angkor or Lavodayapura, while much of the work was local.^[152] Its irregular construction and sandstone bases bearing Late Angkorian script and language suggest that some parts may have been completed or altered after Jayavarman VII's reign.^[153] Excavation has yielded only a small amount of Ming Chinese ceramic alongside Sukhothai wares, providing little evidence for sustained occupation after the Angkorian period.^[151]: 2

Lavo's relationship with Angkor also appears to have been flexible. One interpretation places Lavo under Angkorian control throughout the period, with independent missions to China during Angkorian succession disputes and independence before 1289. Baker and Pasuk instead point to evidence of local autonomy: in Suryavarman II's procession at Angkor Wat, Jayasinhavarman of Lavo appears prominently with his troops; Suryavarman II patronised Buddhism at Lopburi; and Lopburi rulers maintained marriage ties with both Pagan and Angkor.^{[13]: 23–4}

Chinese merchants recorded several polities between 1103 and 1115, including Zhēn Lǐ Fù, Róng Lǐ, Luó Hú, and Xún Fān, some tentatively located in the lower Menam basin.^[154]: 129 Conflicts among them are possible during this transitional phase.^[155]: 13

Epigraphy also points to growing linguistic diversity in the lower Menam basin. Thai lexical items occur in inscriptions otherwise written in Pali, Sanskrit and Old Khmer, including K.766 of 1167, K.995 of 1213, and the Mueang Sing inscription (กจ. 4), tentatively dated to the 13th or 14th century.^{[156]: 50–1} Their scripts differ markedly from those in the Phimai, Surin, Buriram and Angkor regions within Jayavarman VII's sphere.^{[156]: 52–4} The latest records the local ruler Phraya Chaiyakon (พฺรญาไชยกร).^{[156]: 50–1} Comparable linguistic evidence appears in the Phra Aiyakan Betset, an original section of the pre-Ayutthaya legal manuscript with an internal date corresponding to 1224 CE,^[157] written entirely in Thai and displaying archaic features and phraseology reminiscent of the Sukhothai Ram Khamhaeng Inscription.^{[158]: 45–59}

Emergence of Siamese polities

Later traditions and epigraphy describe several regional ruling lines emerging in the Menam valley during the 12th century. After Sri Dharmasokaraja I moved to Nakhon Si Thammarat in 1117, readings of the Dong Mè Nang Mưo'ng Inscription (K.766)^[159] of 1168^[145]: 38 state that his successor Sri Dharmasokaraja II recovered Lavo in 1157^[145]: 47 and extended his authority north towards present-day Nakhon Sawan,^{[145]: 40 [155]: 12} and sought to retain the allegiance of Dhanyapuri, which is also named in the inscription.^[155]: 13

Later traditions likewise describe several Siamese centres shifting northward. The Ayutthaya Testimonies place Suryaraja at Kamphaeng Phet from 1156,^[51]: 11 while Pra Poa Noome Thele Seri, in Du Royaume de Siam and the Instructions Given to the Siamese Envoys Sent to Portugal (1684), is said to have moved to the Nakhon Thai–Sukhothai region in 1155.^{[64][66]: 127} His younger brother Uthong I is placed at Chaliang by the Northern Chronicle.^{[62]: 60–1} These rulers are then described as returning to the lower western Menam valleys, including Suphannaphum–Phrip Phri–Jayasimhapuri,^{[64][51]: 46} during the 1160s,^[155]: 61 with Jatiraja (ชาติราชา) at Jayasimhapuri and Pra Poa Noome Thele Seri succeeding him in the 1170s.^{[51]: 45–46} The line associated with Suryaraja instead expanded northward and formed alliances with Tai chiefdoms, later associated with the political formation conventionally identified as the Sukhothai Kingdom.^{[51]: 11–29}

The Nakhon Si Thammarat Chronicle [th] similarly records fighting in the lower valleys and Sri Dharmasokaraja's extension of authority over Menam polities. Although it calls him ruler of Nakhon Si Thammarat, it places him at an unnamed northern seat. After the riverine powers recovered these territories, he withdrew south to Nakhon Si Thammarat; they pursued him down the Malay Peninsula in the 1190s, ending in a negotiated settlement near present-day Prachuap Khiri Khan.^[145]: 41

Tai–Xiān–Angkorian interactions across the Mekong and Menam basins

The nine-year contest between the Angkorian claimants Jayavirahvarman of the Phimai region and Suryavarman I of the eastern and northeastern territories ended in Suryavarman's victory in 1010. He is said to have campaigned against several cities in the Phimai region and then taken over polities in the Preah Vihear region associated with the Mahidharapura clan, forcing the lineage northward.^{[129][130]: 120–1} Its destination is disputed; some scholars propose present-day Sakon Nakhon, citing a large triangular moated settlement with Angkorian-period artefacts and Mahidharapura-era remains.^[131]

The Mahidharapura line may subsequently have encountered a Tai Lueang (ไทเลือง) polity and married into its ruling house. An inscription records the Tai prince Pha Mueang marrying Sukhara Mahadevi, a Mahidharapura princess often identified as a daughter of Jayavarman VII.^[132] The Tai Lueang lineage also became connected to the northern Xiān polity of the Menam basin through the marriage of Pha Mueang's sister Nang Sueang [th] to Si Intharathit, then governor of Mueang Bang Yang, identified with present-day Nakhon Thai.^[160] The lineage is also associated with Mueang Rad in the upper Menam basin, tentatively identified by some scholars with Mueang Thung Yang [th] in Uttaradit.^{[134]: 54–9} Comparable dynastic links may have extended southward: the Northern Chronicle relates that the Tai prince Jayasena, identified as Phichai Chiang Mai, married a princess of the southern Xiān ruling line and succeeded his father-in-law as ruler of Ayodhya.^{[62]: 66–7}

The Sakon Nakhon hypothesis receives some support from a Vietnamese inscription of 1159 commemorating Duke Đỗ Anh Vũ. It records that in 1135 Văn Đan, generally identified with present-day Vientiane and described as under Zhenla, attacked Nghệ An and was pursued by the duke.^[161]: 65 Later Chiang Mai and Chiang Saen traditions describe Tai groups from this region, including those associated with Candrapuri, Muang Sua and Mueang Kaew Prakan, attacking Ngoenyang in the 1150s. The campaigns are said to have been defeated by the legendary Chueang, who brought the invading polities under his authority.^{[162]: 9 [163]: 76–83}

The same period is reflected in the Tamnan Fa Daet Song Yang (ตำนานฟ้าแดดสงยาง), which describes political fragmentation in the northern and central Korat Plateau following the movements associated with Chueang. It does not mention the Angkorian-associated Phaya Khom and Muang Nong Han or Saket Nakhon Roi Et Pratu, but instead describes new royal lineages moving south from the north. One established itself at Muang Fa Daet–Muang Song Yang and allied with four southern muang, while another established a small mandala centred on Muang Chiang Som in the Lam Pao basin and allied with Chiang Yun in the middle Chi basin. The legend describes repeated conflict between the two factions, with the defeated side periodically becoming tributary to the victor before the relationship was reversed.^{[79]: 500–5} Its final campaign lists numerous allied muang and ends with a decisive victory for Chiang Som, although the historical identities of many of these places remain unstudied.^[164]

Following the Mahidharapura dynasty's successive recoveries of the Angkorian throne under Jayavarman VI in the 1080s^[130]: 137 and Jayavarman VII in the 1180s, the Tai Lueang polity led by Sri Naw Nam Thum and Pha Mueang appears to have expanded through the upper Menam basin. It is said to have taken control of Chaliang and later Sukhothai, overthrowing the Mon ruler E Daeng Phloeng around 1219.^{[165]: 15–6 [166][167]: 115} An epigraphic account associated with the Khom Sabat Khlon Lamphong corpus, however, suggests a later shift to another ruling lineage. This may have prompted a joint intervention by the allied Tai Lueang and Xian rulers, whose forces under Pha Mueang and Si Intharathit are described as removing the rival ruler and restoring their influence over Sukhothai in 1238. In later reconstructions of early Thai political history, this event has been treated as one of the formative episodes associated with the foundation of the Sukhothai Kingdom.^{[8]: 195–196}

Formation of Ayodhya

Around the 1180s^[i]–1190s, following the loss of Lavo in 1157, Angkorian authority is said to have been reasserted in the region.^[145]: 39 The Prasat Tor Inscription records that Jayavarman VII defeated a "monarch of the west" in either 1189/90 or 1195/96,^[44]: 24 while reports place Sri Dharmasokaraja II again at Nakhon Si Thammarat.^[145]: 41 In the same period,^[j] Chinese sources describe the central Menam valley as controlled by its former ruling line under Pra Poa Noome Thele Seri and known as Chen Li Fu.^[168]: 1 The polity has been broadly associated with Indaprasthanagara, whose proposed centre lies in the Phraek region and which may have survived into the 13th century.^[k] The Ayutthaya Testimonies place its dynasty in the same lineage as the early Sukhothai rulers,^{[51]: 16–7} while Walailak Songsiri suggests that the Indic name of the Chen Li Fu ruler may have been adopted as a formal title for relations with China and may reflect wider dynastic ties.^[126]: 7

The 1225 Zhu Fan Zhi, however, lists Lavo, Chu fan chi, and Pagan among the tributary states of Angkor. Earlier scholarship identified Pagan with the lower Irrawaddy basin, while another interpretation places it in the lower Menam basin under Sri Dharmasokaraja II.^[44]: 25 The latter draws on the Phatthalung version of the Legend of Nakhon Si Thammarat, which says that his father came from Bago in Myanmar,^[170]: 28 while Chu fan chi is generally identified with Chen Li Fu.^[44]: 25

In the lower western valley, a southern Siamese lineage is said to have claimed the throne of Ayodhya in 1205 through royal intermarriage, under the Siamese–Mon–Chinese–Cham-heritage ruler Uthong II.^[128] The new seat replaced Indaprasthanagara of Chen Li Fu. The dynasty formed further marriage alliances with the Mon ruling house of Haripuñjaya at Chaliang,^{[62]: 69–71 [128]} producing the mixed Mon–Chinese princes Dhammaraja and Baramaraja, who later ruled Ayodhya.^[128] Some scholars have consequently argued that Chinese support contributed to the Siamese seizure of power at Ayodhya.^[59]: 84 The polity was identified as Xiān in several Chinese and Đại Việt sources.^[117]

A prince of this lineage, Varashreṣṭhakumāra, who ruled at Phrip Phri, later ascended the Ayodhya throne as Ramathibodi I (Uthong V) in 1341.^[128] He strengthened his position through marriage alliances with Lavo to the east and the Tai–Siamese Suphannaphum to the west.^[155]: 61 The subsequent integration of these centres in the lower river valleys culminated in the traditional foundation of the Ayutthaya Kingdom in 1351.^[171]

By the late 14th and 15th centuries, former Dvaravati principalities, including Lavo, Suphannaphum, and the northern cities of the former Sukhothai Kingdom, had been incorporated into Ayutthaya, a process described as complete by 1438.^[172]: 274

Pre-Lan Xang political networks in the Korat Plateau

With the Dvaravati and Angkorian networks in decline, the Khorat Plateau became a frontier in the late 13th and early 14th centuries where three spheres overlapped: the declining authority of Angkor over its Mahidharapura- and Sakon Nakhon-linked networks, the expanding Siamese kingdoms of Sukhothai and later Ayutthaya, and the Lao mueang of the middle Mekong, united by Fa Ngum as Lan Xang in 1353. Direct epigraphic and archaeological evidence is thin, so the political geography is reconstructed largely from later chronicles, retrospective place names, and comparison with Angkorian and early Lao sources, leaving many identifications provisional.

A long-standing debate concerns the location of Mueang Rad, the polity ruled by Pho Khun Pha Mueang (fl. late 12th – mid 13th-c.) in the traditional founding narrative of Sukhothai. Manit Vallibhotama identified it with the moated site of Mueang Kao (Khorakhapura, also called Nakhon Raj)–Mueang Sema [de] in modern Sung Noen, Nakhon Ratchasima,^[173] while Chit Phumisak later supported the identification through toponymic analysis. Other scholars place Mueang Rad in the lower Nan basin near modern Uttaradit^{[134]: 54–9 [13]: 35} or the Pa Sak Valley in Phetchabun, or suggest that Pho Khun Pha Mueang ruled more than one polity.^[174] The Khorat hypothesis has also been questioned because the Phimai corridor appears to have remained aligned with Angkor until the early 15th century, when Ayutthaya launched a separate campaign to secure the region before the sack of Angkor Thom in 1431.^[175] The Lao chronicle tradition offers another perspective: the Lan Xang Chronicle records Fa Ngum's conquest of Mueang Phrommathat, identified by later scholars as Phimai, followed by campaigns against other centres across the Khorat Plateau. Because these accounts were compiled centuries later and incorporate legendary material, their place identifications remain tentative.

Archaeology gives a different picture. Surveys of early Lan Xang settlement centre on the Loei–Nong Bua Lam Phu–Udon Thani–Nong Khai corridor, where securely dated sites lie west of the Phu Phan Range,^[176][177] and have been interpreted as a frontier network associated with Fa Ngum's reign along the Phetchabun and Phu Phan corridors.^[176][177] This leaves much of the central plateau outside the initial archaeological network, in contrast to chronicle identifications that place several conquered mueang around Phimai. Most inscriptions from the region date only from the later Vientiane period,^[178] leaving the two reconstructions unreconciled. The southern and southeastern margins of the plateau continued to be inhabited by Kuy communities, whose presence predates the documented Kuy chiefdoms of the 18th century.^[179] A proposed Kuy polity centred on Tbong Khmum in the 14th–16th centuries likewise rests mainly on later chronicles and lacks archaeological or epigraphic corroboration.^[180] Beyond the plateau, southern Laos and northeastern Cambodia were likewise divided among small riverine polities around Champasak, Salavan, and Attapeu. Later interpretations of Fa Ngum's campaigns place these areas within Lan Xang, but archaeological evidence for the immediately pre-Lan Xang period remains limited.^[181][182]

Lao and Siamese chronicles describe a frontier settlement between Lan Xang and Ayutthaya after Fa Ngum's campaigns, accompanied by a royal marriage alliance between Fa Ngum and an Ayutthayan princess.^{[183]: 103 [184][185]}