Treaty of Sugauli

Following the Unification of Nepal under Prithvi Narayan Shah, Nepal attempted to enlarge its domains, conquering much of Sikkim in the east and, in the west, the basins of Gandaki and Karnali and the Uttarakhand regions of Garhwal and Kumaon. This brought them into conflict with the British, who controlled directly or indirectly the northeastern Indian plains between Delhi and Calcutta. A series of campaigns termed the Anglo-Nepalese War occurred in 1814–1816. In 1815 the British general David Ochterlony evicted the Nepalese from Garhwal and Kumaon across the Kali River,^[3][4] ending their 12-year occupation, which is remembered for its brutality and repression.^[5][6]

Octherlony offered peace terms to the Nepalese demanding British suzerainty in the form of a British resident and the delimitation of Nepal's territories corresponding roughly to its present-day boundaries. The Nepalese refusal to accede to the terms led to another campaign the following year, targeting the Kathmandu Valley, after which the Nepalese capitulated.^[7][8]

Historian John Whelpton writes:

Negotiations for a general settlement produced a draft which was initialled at Sagauli in Bihar in December 1815 and required Nepal to give up all territories west and east of its present-day borders, to surrender the entire Tarai and to accept a permanent British representative (or 'resident') in Kathmandu. The Nepalese government initially balked at these terms, but agreed to ratify them in March 1816 after Ochterloney occupied the Makwanpur Valley only thirty miles from the capital.^[9]

Nepal boasts a salt trade route to Tibet that has been in use for many centuries. This was significant to the economic well-being of the Kathmandu valley. As the British East India Company had profited from Indian trade routes, Nepal's trade routes were desirable to conquer.

Nepal was a relatively newly established nation that did not have well-established boundaries with law enforcement around the supposed borders. In conjunction with its frustration with this, and its desire for the trade routes, the East India Company declared war against Nepal known as the Anglo-Nepalese War from 1814 to 1816.^[10] Nepal's advantage lay in their highly esteemed army of men known as the Gurkhas who were also of interest to the company. As a smaller and less developed country, Nepal eventually relented in the war and agreed upon a ceasefire under the terms and conditions of the Sugauli Treaty.^[11]

Three of the main goals of the company were to employ Nepal's impressive army, establish a presence of supervision in the Nepali court, and utilise its trading routes to Tibet.^[12] Naturally, the decision to sign the treaty was not treated with full acceptance by the Nepali court and roused a large point of controversy. Bhimsen Thapa, Nepal's prime minister at the time “realised that the best way to ensure Nepal’s continued freedom from interference was to grant the governor-general’s basic desire, a secure and trouble-free border”. In attempts to mitigate the infringement on Nepal's sovereignty and internal security, the treaty was signed.^[13] From the British perspective, the costs of colonising Nepal were impractical in comparison to placing certain aspects of the country under British control.^[14]

The treaty stipulated that Nepal's government structure be without external interference and that aside from the singular British resident in the Nepali court, their national affairs would not be compromised. In addition to the benefit of Nepal's continued sovereign independence, an alliance was established between the two governments.^[15]

Article 5 of the treaty required Nepal to cede "the whole of the lowlands between the rivers Kali and Rapti" and "all the hill territories" west of the Kali River.^[16] The Kali River was thus established as the western boundary of Nepal, and the annexed territories of Kumaon and Garhwal came under British administration.

The treaty saw three decades of peace following its implementation, however, other issues began to arise starting in 1840.  

“An army mutiny over proposed pay reductions almost turned into an attack on the British residency because the soldiers were led to believe that the cuts had been forced on the Nepalese government by the British”^[20] in June 1840"

This followed as a result of suspicions that arose in the Nepali court that its independence in internal government affairs was being infringed upon.^[21] Another incidence of alarm occurred in 1842 during a debt lawsuit over an Indian Merchant, Kasinath Mull. The British resident in the Nepalese court, Brian Hodgson appeared hostile and assertive, implicating attempted control over the independence of decision in the court. Through these issues, the success of the treaty's attempt to buffer tensions may still be debated.^[22]

• Nepal–Britain Treaty of 1860
• 1950 Indo-Nepal Treaty of Peace and Friendship
• Gurkha War
• Kingdom of Nepal
• Naya Muluk - land in western Terai restored to Nepal in 1860
• Prithvi Narayan Shah
• Sikkim
• Unification of Nepal
• Byans
• Kalapani territory
• Kuthi Valley
• Tinkar Valley
• Bam Shah