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 Hong Kong one of the colony's wealthiest people by this time. During China's turbulent period in the 20th century, Hong Kong served as a safe haven for dissidents, political refugees, and officials who lost power. British policy allowed dissidents to live in Hong Kong as long as they did not break local laws or harm British interests. The implementation of this policy varied according to what the senior officials thought constituted British interests and the state of relations with China. The Canton–Hong Kong strike (1925–1926) was anti-imperialist in nature. The 1966 riots and Maoist-led 1967 riots, essentially spillovers from the Cultural Revolution,