Hong Kong(Chinese: 香港), officially the Hong Kong Special Administrative Region , is one of the two special administrative regions of the People's Republic of China (PRC), the other being Macau. The territory lies on the eastern side of the Pearl River Delta, bordering Guangdong province in the north and facing the South China Sea in the east, west and south. Beginning as a trading port in the 19th century, Hong Kong has developed into a leading financial centre. Hong Kong was a crown colony of the United Kingdom from 1842 until the transfer of its sovereignty to the People's Republic of China in 1997. The Sino-British Joint Declaration and the Basic Law of Hong Kong stipulate that Hong Kong operates with a high degree of autonomy until at least 2047, fifty years after the transfer. Under the policy of "one country, two systems", the Central People's Government is responsible for the territory's defence and foreign affairs, while Hong Kong maintains its own legal system, police force, monetary system, customs policy, immigration policy, and delegates to international organisations and events.