Hong Kong), officially the Hong Kong Special Administrative Region of the People's Republic of China (HKSAR), is a city and special administrative region of China on the eastern side of the Pearl River estuary in southern China. With over 7.4 million people of various nationalities in a 1,104-square-kilometre (426 sq mi) territory, Hong Kong is one of the most densely populated places in the world.
Hong Kong became a colony of the British Empire after 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 territory was returned to China in 1997. As a special administrative region, Hong Kong maintains separate governing and economic systems from that of mainland China under the 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. As one of the world's leading international financial centres, Hong Kong has a major capitalist service economy characterised by low taxation and free trade, and the currency, Hong Kong dollar, is the eighth most traded currency in the world. Hong Kong hosts the largest concentration of ultra high-net-worth individuals of any city in the world. Although the city has one of the highest per capita incomes in the world, there is severe income inequality among its residents.Hong Kong is a highly developed territory and ranks fourth on the UN Human Development Index. The city also has the largest number of skyscrapers of any city in the world and its residents have some of the highest life expectancies in the world. The dense space also led to a developed transportation network with public transport rates exceeding 90 percent. Hong Kong is ranked third in the Global Financial Centre Index, behind New York City and London. In an annual ranking of the Index of Economic Freedom, Hong Kong has come out on top 25 years in a row, according to the Heritage Foundation, a U.S. think tank.