Dharmatriloka

Dharmatriloka (Thai: ธรรมไตรโลก) was a 12th-century Siamese monarch attested in the Northern Chronicle as the ruler of Mueang Chaliang (modern Si Satchanalai).^{[1]: 65–6} He succeeded his father, Suvacanaraja, in the late-12th century.^{[1]: 69–70} Dharmatriloka is recorded to have had a long reign and to have contracted marriage with a Chinese princess,^[a] with whom he had three sons: Dhammaraja, Baramaraja, and Rajadhiraj II.^{[1]: 69–70 [2]: 24} He is explicitly identified as a direct relative of the ruler of Oghapurī (โอฆะบุรี; modern Phichit),^{[1]: 65–6} a polity said to have been established by a descendant of Padumasūriyavaṃśa in the 8th century.^[3]: 11

The early reign of Dharmatriloka is described in the Northern Chronicle as a period of stability and religious devotion. The records attribute to him duties and activities primarily concerned with the patronage of Buddhism.^{[1]: 65–6} Royal intermarriages with the southern polity of Xiān are also recorded, involving his two elder sons, Dhammaraja and Baramaraja.^{[1]: 69–71 [2]: 24–5 [4]} In the middle and later periods of his reign, it is speculated that the polity may have encountered the political and military expansions of Angkor under the rule of Jayavarman VII or by other Angkor-related nobles,^[2]: 25 whose dynasty successfully regained Lavo^[5]: 39 and established dynastic relations with Xiān monarchs in the Phraek Si Racha region, which was known as Chen Li Fu in the late 12 century.^{[6]: 20–1 [7]: 7–11}

Succession initially favored the eldest prince, Dhammaraja. However, both Dhammarāja and Baramaraja entered into matrimonial alliances with princesses of King Suvarnaraja of Ayodhya and consequently were not permitted to return to Mueang Chaliang.^[1]: 70 Each subsequently ascended the throne of Ayodhya, succeeding their father-in-law, with Dhammarāja reigning from 1301 to 1310, and Baramarāja from 1310 to 1344.^[4] The succession of Mueang Chaliang, therefore, passed to the youngest prince, Rajadhiraj II.^[2]: 25