Explanation:

The Treaty of Sugauli (also spelled Sugowlee, Sagauli and Segqulee), the treaty that established the boundary line of Nepal, was signed on 2 December 1815 and ratified by 4 March 1816 between the East India Company and King of Nepal following the Anglo-Nepalese War of 1814-16. 

The signatory for Nepal was Raj Guru Gajraj Mishra aided by Chandra Sekher Upadhayaya, the signatory for the Company was Lieutenant Colonel Paris Bradshaw. Under the treaty, some of the Nepalese controlled territory was lost including all the territories that the King of Nepal had won in wars in the last 25 years or so such as the Kingdom of Sikkim in the east, Kumaon Kingdom and Garhwal Kingdom (also known as Gadhwal) in the west. Some of the Terai lands were restored to Nepal in 1816 and more were restored in 1860 to thank for helping the British to suppress the Indian rebellion of 1857.