The Battle of Chinkiang was fought between British and Chinese forces in Chinkiang (Zhenjiang), Jiangsu province, China, on 21 July 1842 during the First Opium War. It was the last major battle of the war. The Chinese force consisted of a garrison of Manchu and Mongol Bannermen. In command of the British forces was Sir Hugh Gough. Leading one brigade was future British field marshal Sir Colin Campbell. The British capture of this stronghold allowed them to proceed to Nanking. Fought near the confluence of the Grand Canal and Yangtze River, the battle effectively blocked operation of the Caoyun system, a transport network vital for the movement of grain throughout the empire. As a result, the Daoguang Emperor decided to sue for peace and agreed to sign the Treaty of Nanking, which brought hostilities to an end. Mass suicide was committed by the Manchu Bannermen who were defending the city.