1688 was an exceptional year in world history. This year, “Glorious Revolution” took place in Britain, power in country passed to Parliament, and royal power was limited. In east, in Nerchinsk, territorial negotiations were held between Romanov dynasty of Russian Empire and Qing dynasty of China. These negotiations established border situation between China and Russia for next 170 years. In second year, both sides signed "Nerchinsk Treaty", in which Waixinan Mountains were dividing line between two countries. In fact, Qing dynasty made a big concession, that is, renounced territorial claims around Lake Baikal. What is happening here?
Lake Baikal, lake with largest reserves of fresh water in world, has been quietly lying in south of Siberia for thousands of years. The ancient Chinese knew little about lake, and even nomads in Mongol highlands were relatively unfamiliar with it. Some say that North Sea, where Su Wu herds sheep, is Lake Baikal, but this is just a guess. There is almost no exact information about Lake Baikal in literature before Yuan dynasty in China. Before Yuan Dynasty, it began to appear. After emergence of Mongol Khanate, Genghis Khan once sent troops to conquer forest peoples in north - Buryatia and included Lake Baikal in his territory. Judging by name, Buryats may be a fishing and hunting people.
During Ming Dynasty, Buryatia still belonged to desert Mongolia, but was not closely connected to much of Mongolia's Khalkha, which also gave Russia a convenient opportunity to invade. Beginning in 1598, Russia began to invade Siberia, and by 1647 it had advanced as far as Sea of Okhotsk. During this period, Buryatia Mongolia was easily conquered by Russia. Beginning in 1631, Buryats launched a 25-year resistance struggle, but were eventually isolated and defeated. This area was never visited during Ming Dynasty and was not reached at beginning of Qing Dynasty, so it was occupied by Russia.
However, at negotiations in 1688, Qing dynasty nevertheless put forward claims to Buryatia. In May 1688, Suoetu, a minister of Qing Dynasty, proposed that "Nerchinsk, Yaksa, Heilongjiang, and rivers and streams leading to them all belong to our land and should not be given to Oros". During negotiations, Soetu suggested from very beginning that Lena River should be border and Lake Baikal also belong to China, but Russian negotiator Golovin did not lag behind, stating that "the Baikal region has been royal land since ancient times" and wants to divide this land along border of Heilongjiang. In fact, Russia occupied Lake Baikal a step earlier than Qing dynasty, which made territorial claims because they believed that Qing dynasty emperor was also Great Khan of Mongolia, and Buryatia was part of Mongolia.
Just as negotiations between two sides stalled, Galdan, leader of Dzungar Khanate to northwest, led Mongol cavalry across Mongol Plateau and his front reached Ulan Butong, near Beijing. . Galdan traveled thousands of miles to challenge Kangxi Emperor, which doubled pressure on Qing Dynasty. At this time, Suoetu decided to compromise with Russia, i.e. use Gerbitsi River and Ergun River as a border to define boundary between two countries west of Xinan Mountains. At this time, Soetu proposed dividing borders between Chinese Mongolia and Russian Siberia, but Russian negotiators refused. Golovin believed that Mongolia was under jurisdiction of Dzungars, and Qing dynasty did not border Buryatia, so there was no need for negotiations. . Thus, negotiations were terminated at this point.
After signing of Nerchinsk Treaty, Kangxi conquered Galdan three times and included Karkin Mongolia into Qing dynasty, which made it possible for Qing dynasty and Russia to negotiate again. At this time, Russia and Qing Dynasty began a second round of rivalry. Russia secretly supported Dzungar Khanate to counter Qing Dynasty, and Kangxi sent envoys to Volga River basin to read an imperial decree to Turgut tribe, which moved west from Mongolia. After several skirmishes, both sides decided to negotiate again. In 1724, Catherine I sent negotiators, but they were not going to give up Baikal region. Catherine I gave negotiators a secret rule: border with China should be drawn along the map of Siberia drawn by Russia. Based on this, Russia cannot abandon Baikal, Udinsk, Selengosk and Nerchinsk. That is, Russia is not going to spit out a piece of land.
In fact, Qing Dynasty did not really want Baikal, because biggest concern of Qing Dynasty was Dzhungar. In 1727, Russia and Qing dynasty signed "Treaty of Kyakhta", which demarcated border between two countries in Mongolian region. The Qing dynasty recognized that Buryatia Mongolia belongs to Russia, and Russia recognized that Karka Mongolia belongs to China. So far, Qing dynasty has completely abandoned its land claims around Lake Baikal.
Both Nerchinsk Treaty and Kyakhta Treaty are equal treaties, and their legal force is very high. Although Qing dynasty renounced its territorial claims to Lake Baikal, this did not mean that Qing dynasty ceded land. Because neither Ming dynasty nor Qing dynasty controlled this piece of land, and Russia occupied it until Qing dynasty came to power. Therefore, from point of view of "from ancient times", perhaps Russia has more reason to speak.