Aigun Treaty

The Treaty of Aigun (Russian: Айгунский договор; simplified Chinese: 瑷珲条约; traditional Chinese: 璦琿條約; pinyin: Àihún Tiáoyuē) was an 1858 unequal treaty between the Russian Empire, and the empire of the Qing Dynasty, the Manchu rulers of China, that established much of the modern border between the Russian Far East and Manchuria (the original homeland of the Manchu people and the Qing Dynasty), which is now known as Northeast China. It reversed the Treaty of Nerchinsk (1689) by transferring the land between the Stanovoy Mountains and the Amur River from China (Qing Empire) to the Russian Empire. Russia received over 600,000 square kilometres (231,660 sq mi) from China.

Since the 18th century, Russia had desired to become a naval power in the Pacific. It did so by establishing naval outposts near the River Amur watershed, encouraging Russians to go there and settle, and slowly developing a strong military presence in the region. China never governed the region effectively or conducted territorial surveys, and these Russian advances went unnoticed.

From 1850 to 1864, China was heavily fighting the Taiping Rebellion, and Governor-General of the Far East Nikolay Muraviev camped tens of thousands of troops on the borders of Mongolia and Manchuria, preparing to make legal Russian de facto control over the Amur from past settlement. Muraviev seized the opportunity when it was clear that China was losing the Second Opium War, and threatened China with a war on a second front. The Qing Dynasty agreed to enter negotiations with Russia.

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