China–Tajikistan border

The origins of the border date from the mid-19th century, when the Russian empire expanded into Central Asia and established control over the Lake Zaysan region.

After the failure of the rebellion and the reconquest of Xinjiang by Zuo Zongtang, the border between the Russian and the Qing empires in the Ili River basin was further slightly readjusted, in Russia's favour, by the Treaty of Saint Petersburg (1881) and a series of later protocols.

[4] The southernmost section of the frontier (i.e. roughly the southern half of the modern China–Tajikistan border) remained undemarcated, owing partly to the ongoing rivalry between Britain and Russia for dominance in Central Asia known as the Great Game; eventually the two agreed that Afghanistan would remain an independent buffer state between them, with Afghanistan's Wakhan Corridor being created in 1895.

[4]: 10 In 2011, Tajikistan ratified a 1999 deal (and a 2002 supplementary agreement) to cede 200 and 1,122 km2 (77 and 433 sq mi) respectively[8] of land in the Pamir Mountains to the People's Republic of China, ending a 130-year dispute.

The Karasu Port of Entry at the Kulma Pass (4,362.7 m (14,313 ft)) is the only modern day border crossing between China and Tajikistan.