Hong Kong has been part of the territory of China since ancient times; it was occupied by Britain after the Opium War in 1840. On 19 December 1984, the Chinese and British Governments signed the Joint Declaration on the Question of Hong Kong, affirming that the Government of the People's Republic of China will resume the exercise of sovereignty over Hong Kong with effect from 1 July 1997, thus fulfilling the long-cherished common aspiration of the Chinese people for the recovery of Hong Kong.
Upholding national unity and territorial integrity, maintaining the prosperity and stability of Hong Kong, and taking account of its history and realities, the People's Republic of China has decided that upon China's resumption of the exercise of sovereignty over Hong Kong, a Hong Kong Special Administrative Region will be established in accordance with the provisions of Article 31 of the Constitution of the People's Republic of China, and that under the principle of "one country, two systems", the socialist system and policies will not be practised in Hong Kong. The basic policies of the People's Republic of China regarding Hong Kong have been elaborated by the Chinese Government in the Sino-British Joint Declaration.
In accordance with the Constitution of the People's Republic of China, the National People's Congress hereby enacts the Basic Law of the Hong Kong Special Administrative Region of the People's Republic of China, prescribing the systems to be practised in the Hong Kong Special Administrative Region, in order to ensure the implementation of the basic policies of the People's Republic of China regarding Hong Kong.