In 1775, Atake Tynay Biy Uulu, one of the leaders of Sarybagysh tribe, established first diplomatic ties with the Russian Empire by sending his envoys to Catherine the Great in Saint Petersburg. In the early 19th century, the territory of Kyrgyzstan came under the control of the Khanate of Kokand, but the territory was occupied and formally annexed by the Russian Empire in 1876. The Russian takeover instigated numerous revolts against tsarist authority, and many Kyrgyz opted to move into the Pamir Mountains or to Afghanistan. The ruthless suppression of the 1916 rebellion in Central Asia, triggered by the Russian imposition of the military draft on the Kyrgyz and other Central Asian peoples, caused many Kyrgyz to flee to China. For Russian expansion into central Asia see Russian conquest of Turkestan.