evidence: China pledged to preserve much of what makes Hong Kong unique when the former British colony was handed over in 1997. Beijing said it would give Hong Kong fifty years to keep its capitalist system and enjoy many freedoms not found in mainland Chinese cities. [...] Hong Kong is a special administrative region of the People’s Republic of China that has, until recently, largely been free to manage its own affairs based on "one country, two systems," a national unification policy developed by Chinese leader Deng Xiaoping in the 1980s. The concept was intended to help integrate Taiwan, Hong Kong, and Macau with sovereign China while preserving their unique political and economic systems. After more than a century and a half of colonial rule, the British government returned Hong Kong in 1997. (Qing dynasty leaders ceded Hong Kong Island to the British Crown in 1842 after China’s defeat in the First Opium War, and Kowloon and the New Territories came under British rule shortly after.) Portugal returned Macau in 1999, and Taiwan remains independent. The Sino-British Joint Declaration of 1984 dictated the terms under which Hong Kong was returned to China. The declaration and Hong Kong’s Basic Law, the city’s constitutional document that Beijing enacted in accord with the declaration, enshrined the city’s "capitalist system and way of life" and granted it "a high degree of autonomy," including executive, legislative, and independent judicial powers for fifty years (until 2047).