1792: The Tibetan Ganden Phodrang regime became a protectorate of Qing China in the mid-18th century. Nyalam Town (Kuti) on the western bank of the Poiqu River (also known as the Bhotekoshi River in Nepal) had long been a strategic location for trans-Himalaya trade and military operations. Nepal invaded Tibet through Nyalam in 1788 and renounced all claims of influence in Tibet after losing the Sino–Nepalese War (1788–1792).

 

1839: Qing authority over Tibet weakened gradually in the latter half of the 19th century given the weight of Qing’s domestic and foreign-relations burdens, particularly, the Opium War (1839–1842 and 1856–1860) and Taiping Civil War (1850–1864).

 

1850: Russian and British rivalry for control of Central Asia prompted the Tibetan government to ban all foreigners and shut borders.

 

1855: During the Nepalese–Tibetan War (1855–1856), the Nepalese army occupied Burang, Gyirong, Nyalam, and Rongshar. The war was ended by the 1856 Treaty of Thapathali, in which Nepal recognized Qing’s suzerainty over Tibet, and the Tibet government agreed to not impose customs duties for Nepalese products.

 

1904: Britain began discreetly mapping Tibet in the 1860s for military and commercial purposes, and the entire southern flank of Tibet was under the control of the British Raj by the 1890s. Following the British military expedition to Tibet (1903–1904), Britain forced Tibet to sign a trade agreement in 1904 to forestall any Russian overtures.

 

1911: Qing reasserted its authority shortly after the British military expedition to Tibet, and Britain and Russia acknowledged Qing’s suzerainty over Tibet in 1907. After Qing was overthrown during the 1911 Chinese Revolution, Tibet became a de facto independent state, comprising the western half of the Tibetan Plateau before the 1951 annexation by the People’s Republic of China (PRC).

 

1951: Soon after its establishment in 1949, the PRC enforced a long-held claim to Tibet and started a military campaign in 1950 after months of failed negotiations on the status of Tibet. The campaign resulted in the capture of the Chamdo region and annexation of Tibet by the PRC.

1956: Nepal restored diplomatic relations with the PRC in 1955. The two nations signed a new treaty in 1956 terminating the 1856 Treaty of Thapathali, and Nepal recognized Tibet as part of China.

 

1965: Several border ports were established along the China–Nepal border after the signing of the Sino–Nepalese Border Treaty and Sino–Nepalese Treaty of Peace and Friendship in March and April 1960, respectively. Zhangmu Port (2,300 MSL) was established in 1965, which is located 35 km downstream from Nyalam Town (3,750 MSL).

 

1967: Construction of China–Nepal Friendship Highway began in 1963. Opened to traffic in 1967, the highway connects the capital of Tibet, Lhasa, and Zhangmu–Kadori on the Sino–Nepal border and further connects Araniko Highway and Kathmandu, the capital of Nepal.

 

1985: Following the upgrading of Friendship Highway, which is the westernmost part of China National Highway 318 (G318) connecting Tibet with Shanghai in the early 1980s, the Zhangmu–Kadori port was expanded and outcompeted Gyirong­–Rasuwa as the primary trading post between Tibet and Nepal by the mid-1980s.

 

2014: The route between Nepal and China through Zhangmu–Kadori and port facilities were severely damaged by a series of natural disasters, including the 2014 Sindhupalchok landslides and 2015 magnitude 7.8 Nepal earthquake.

 

2019: Zhangmu Port resumed limited operations for goods and vehicles in May after four years of reconstruction.