His next diplomatic exploit was in the Far East, as plenipotentiary to the court of Peking (Beijing). When the Qing Chinese government was terrified by the advance of the Anglo-French expedition of 1860 and the burning of the Summer Palace in the Second Opium War, he worked on their fears so dexterously that, in the Convention of Peking, he obtained for Russia Outer Manchuria – not only the left bank of the Amur, the original object of the mission, but also a large extent of territory and seacoast south of that river that would become the Russian Maritime Province.