Treaty of Aigun
About 1640 Siberian cossacks spilled over the Stanovoy Mountains to the Amur River basin. This land was claimed by the Manchus who at this time were just beginning their conquest of China (Qing dynasty). By 1689 the Russians were driven back over the mountains and the Stanovoy Mountains remained the Russo-Chinese frontier from the Treaty of Nerchinsk (1689) to the Treaty of Aigun in 1859. For a full account see Sino–Russian border conflicts.