to Petersburg. Treaty of Kyakhta (1729) Just before his death, Peter the Great decided to deal with the border problem. The result was the Treaty of Kyakhta. This defined the northern border of what is now Mongolia (except for Tuva) and opened up the Kyakhta caravan trade southeast to Peking. The needs for communication between the Russian and Chinese traders at Kyakhta and elsewhere resulted in the development of a pidgin, known to linguists as Kyakhta Russian-Chinese Pidgin. The treaties of Nerchinsk and Kyakhta were the basis of Russo-Chinese relations until the Treaty of Aigun in 1858. The fixed border helped the Chinese to gain full control of Outer Mongolia and annex Xinjiang by about 1755. Russo-Chinese trade shifted from Nerchinsk to Kyakhta and the Nerchensk trade died out by about 1750. (Local trade in this area shifted east to a border town called Tsurukhaitu on the Argun River). Turkestan After the Russians reached Tobolsk in 1585, it was natural to continue up the Irtysh River to the Kazakh steppes north of Lake Balkhash to Dzungaria and western Mongolia, which was the route used by Fyodor Baykov to reach China. In 1714, Peter the Great sent Ivan Bukholts with 1,500 troops, including Swedish miners who were prisoners of war, up the Irtysh to Lake Zaysan to search for gold. The next year, he ascended the river again with 3,000 workers to build a fort. Tsewang Rabtan (or Tseren-Donduk) of the Zunghar Khanate attacked them and drove them back to Omsk. In 1720, an expedition, under Ivan Likharev, ascended the river and founded a permanent settlement at Ust-Kamenogorsk just west of the lake. Meanwhile, the Zunghars were severely defeated by the Manchus and driven out of Tibet. In 1721 to 1723, Peter sent Ivan Unkovsky to attempt to discuss an alliance. A major reason for the failure was that Lorents Lange at Selenginsk had turned over a number of Mongol refugees to the Manchus as part of the buildup to the Treaty of Kyakhta. In 1755, the Qing destroyed the remnants of the Zunghar Khanate, creating a Russo-Chinese border in Xinjiang. The area did not become active again until the Russian conquest of Turkestan. 1755–1917 Meeting in Central Asia As the Chinese Empire established its control over Xinjiang in the 1750s, and the Russian Empire expanded into Kazakhstan at the beginning and in the middle of the 19th century, the two