The First Anglo-Chinese War (1839-42); known popularly as the First Opium War; was fought between the United Kingdom of Great Britain and Ireland and the Qing Dynasty of China; with the aim of securing economic benefits from trade in (and forcing opium on) China. In 1842; the Treaty of Nanking - the first of what the Chinese called the unequal treaties - granted an indemnity to Britain; the opening of five treaty ports; and the cession of Hong Kong Island; ending the monopoly of trading in the Canton System. The war marked the end of China's isolation and the beginning of modern Chinese history.