[7] While post-WWII Hong Kong saw a population boom with increased migration from mainland China, the traditional ways of life in the indigenous villages in the New Territories collapsed.
Unable to earn a living in the newly industrialised economy of post-war Hong Kong, many villagers exercised their right of abode in the United Kingdom and left for Europe.
Political uncertainties leading up to this transfer of sovereignty, including the 1989 Tiananmen Square protests and massacre in Beijing, prompted some Hong Kong residents to migrate in the 1980s–90s.
[11] In the years following Chinese economic reform, a growing number of Hongkongers have migrated to mainland China, in what is known as the "heading north" (北上) phenomenon.
A key milestone would be the first occasion of tear gassing of peaceful protestors in decades, which at the time was directed by Chief Executive Leung Chun-ying, sparking backlash from the public and precipitated the Umbrella Movement.
The central Chinese government then enacted the Hong Kong national security law to enlarge the power of the police to arrest and detain.