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 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.