China: British and Chinese officials on board HMS Wellesley a day before the capture of Chusan (5-6 July, 1840) in the First Opium War. British Commodore Sir James Gordon Bremer (table, 3rd left) and Chinese Admiral Chang (table, 3rd right), Karl Gutzlaff (centre) served as interpreter. The first capture of Chusan by British forces in China occurred on 5-6 July 1840 during the First Opium War. The British captured Chusan, the largest island of an archipelago of that name. The First Anglo-Chinese War (1839-42), known popularly as the First Opium War or simply the Opium War, was fought between the United Kingdom and the Qing Dynasty of China over their conflicting viewpoints on diplomatic relations, trade, and the administration of justice.