evidence: Seized by the UK in 1841, Hong Kong was formally ceded by China the following year at the end of the First Opium War; the Kowloon Peninsula was added in 1860 at the end of the Second Opium War, and was further extended when Britain obtained a 99-year lease of the New Territories in 1898. Pursuant to an agreement signed by China and the UK on 19 December 1984, Hong Kong became the Hong Kong Special Administrative Region of the People's Republic of China on 1 July 1997. In this agreement, China promised that, under its "one country, two systems" formula, China's socialist economic and strict political system would not be imposed on Hong Kong and that Hong Kong would enjoy a "high degree of autonomy" in all matters except foreign and defense affairs for the subsequent 50 years. Since the turnover, Hong Kong has continued to enjoy success as an international financial center. However, dissatisfaction with the Hong Kong Government and growing Chinese political influence has been a central issue and led to considerable civil unrest.