The Manchu resistance, however, obliged the Russian Cossacks to quit Albazin, and by the Treaty of Nerchinsk (1689) Russia abandoned her advance into the basin of the river, instead concentrating on the colonisation of the vast expanses of Siberia and trading with China via the Siberian trakt. In 1852 a Russian military expedition under Nikolay Muravyov explored the Amur, and by 1857 a chain of Russian Cossacks and peasants were settled along the whole course of the river. The accomplished fact was recognised by China in 1860 by the Treaty of Aigun.