Nepalese invasion of Tibet begins the Nepalese–Tibetan War

Background. Following the Sino-Nepalese War of 1792, Nepal maintained a policy of non-intervention in Tibet. However, by the 1850s, the Qing dynasty's ability to enforce imperial authority in distant regions was crippled by internal rebellions such as the Taiping Rebellion. This weakness allowed Nepalese Prime Minister Jang Bahadur Rana to pursue objectives in Tibet without fear of Chinese interference, setting the stage for renewed conflict.

Grievances and Justification. Jang Bahadur justified Nepalese demands for territorial concessions and indemnities by citing several grievances. These included alleged ill-treatment of an 1852 embassy, abuses suffered by Nepalese Newar traders in Lhasa, and a boundary dispute in the Kuti area. These claims served as the pretext for declaring war in March 1855, with a deadline for conditions set for April 17.

Initial Invasion. In early April 1855, Nepalese troops attacked across major passes between Tibet and Nepal, advancing from Walungchung to Jara. The center of the advance focused on the Kuti and Kerong districts. Reinforcements soon joined the initial forces, bringing the total to 27,000 men equipped with thirty-six guns and eight mortars.

Early Combat Actions. On April 3, General Dhir Shamsher defeated a small Tibetan detachment at Chusan, capturing Kuti and advancing to Suna Gompa. Meanwhile, Bam Bahadur occupied Kerong without opposition. Nepalese forces then pushed toward Dzongka, which became the primary point of Tibetan resistance in the area.