Hong Kong, officially the Hong Kong Special Administrative Region of the People's Republic of China, is a metropolitan area and special administrative region of China in the eastern Pearl River Delta by the South China Sea. With over 7.5 million people of various nationalities in a 1,104-square-kilometre territory, Hong Kong is one of the most densely populated places in the world.
Hong Kong became a colony of the British Empire after the Qing Empire ceded Hong Kong Island at the end of the First Opium War in 1842. The colony expanded to the Kowloon Peninsula in 1860 after the Second Opium War, and was further extended when Britain obtained a 99-year lease of the New Territories in 1898. The whole territory was transferred to China in 1997. As a special administrative region, Hong Kong maintains separate governing and economic systems from that of mainland China under a principle of "one country, two systems".
Originally a sparsely populated area of farming and fishing villages, the territory has become one of the world's most significant financial centres and commercial ports. It is the world's tenth-largest exporter and ninth-largest importer.