Hong Kong is one of two special administrative regions (SAR) of the People's Republic of China; the other is Macau. Situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour. With a land mass of 1,104 km2 (426 sq mi) and a population of seven million people, Hong Kong is one of the most densely populated areas in the world. Hong Kong's population is 95% ethnic Chinese and 5% from other groups. Hong Kong's Han Chinese majority originate mainly from the cities of Guangzhou and Taishan in the neighbouring Guangdong province.
Under the principle of "one country, two systems", Hong Kong's economic and political systems differ from those of mainland China. Hong Kong is one of the world's leading international financial centres, with a major capitalist service economy characterised by low taxation and free trade. Under colonial rule, it espoused minimum government intervention under the ethos of positive non-interventionism. The Hong Kong dollar is the 9th most traded currency in the world.
Hong Kong's independent judiciary functions under the common law framework. Its political system is governed by the Basic Law of Hong Kong, its constitutional document, which stipulates that Hong Kong shall have a "high degree of autonomy" in all matters except foreign relations and military defence. Although it has a burgeoning multi-party system, half of its legislature is controlled by a small-circle electorate. The Chief Executive of Hong Kong, the head of government, is selected by an 800-person Election Committee.
Hong Kong became a colony of the British Empire after the First Opium War. Originally confined to Hong Kong Island, the colony's boundaries were extended in stages to the Kowloon Peninsula and the New Territories by 1898. It was occupied by Japan during the Pacific War, after which the British resumed control until 1997, when China regained sovereignty.