Waves of mass migrations from Hong Kong villagers exercised their right of abode in the United Kingdom and left for Europe. In 1967, a series of large-scale riots erupted in Hong Kong, causing social instability. These events led some of the richer Hong Kong residents to move abroad. Emigration took place to countries in Southeast Asia, South Africa or South American countries. This wave did not come to a rest until the mid-1970s. On the 19th of December 1984, the People's Republic of China and the United Kingdom signed the "Sino-British Joint Declaration", validated the 1997 transfer of sovereignty over Hong Kong to China. The declaration prompted
British nationality law and Hong Kong British nationality law and Hong Kong British nationality law as it pertains to Hong Kong has been unusual ever since Hong Kong became a British colony in 1842. From its beginning as a sparsely populated trading port to today's cosmopolitan international financial centre of over seven million people, the territory has attracted refugees, immigrants and expatriates alike searching for a new life. Citizenship matters were complicated by the fact that British nationality law treated those born in :Hong Kong as British subjects (although they did not enjoy full rights and citizenship), while the People's Republic of China did not recognise