Political map of the Arctic & the Far North 13 August 1859 (Amur Acquisition): Russian expeditions and settlers had been infiltrating China's Amur region since the late 1840s. After the Crimean War exposed the vulnerability of Russia's Pacific possessions to naval attack, the Tsar agreed to back these settlements to consolidate power in the Far East (Amur Acquisition). Taking advantage of China's embroilment in the Second Opium War, the Russians managed to persuade the Chinese to cede first the land to the north of the Amur River (Treaty of Aigun) then, after negotiations between the Chinese and the Allies briefly  broke down, the land to the south (Primorye) (Convention of Peking).