History of modern Hong Kong started at the beginning of XIX century.
Island named as Hong Kong didn't represent anything special about itself before the moment when its became the first British possession in China. It was quite wild and outdated region consisting from few fisherman`s hats. China for Europe was closed, because first Portuguese who appeared here in XVI century were robbing Chinese ships and vessels. As a result all Portuguese including all Europeans were isolated in Macau. But Macau was Portuguese colony, but Britain needed their own support center, and as a result Hong Kong became one of them. With the opening of China Europe discovered a new drink - tea. Britain was paying with silver to buy tea from China, because they didn't accept anything else. Except of ships taking tea to the Europe there were others with silk and spices. Very soon silver stock finished, because China didn't buy back anything for their tea. Eventually there was found a good which was gladly bought in China - opium. Opium trade created first Opium War (1839-1842) between China and Britain, which was ended in 1842, when Treaty of Nanjing was signed, as a result Hong Kong was presented to Britain permanently. English people were that force, which made region to grow in unprecedented temps. Located on a sea route it got important sense of a trade center very fast. Problem of not enough territory on the Hong Kong Island limited widening of Britain colony. Main goal of Britain to start second Opium War (1858-1860) was widening its colony. As a result of 2nd Opium War, Britain got permanently ownership of Kowloon peninsula. In 1898 in a result of next military arguments Britain gets leasing right up to 99 years for the territory on the North of Kowloon peninsula and Lantau island, which got the name New Territory. Due to this simple operation territory of Hong Kong increased in a one time in couple of times.
Hong Kong was formally declared a free port to serve as an entrepot for the British Empire.
On December 8, 1941 Japan attacked Hong Kong. December 25, 1941 battle for Hong Kong finished because of lose of Britain and Canadian forces. Their presence lasted for 3 years and 8 months. Population of Hong Kong decreased from 1.6 million to 600 thousand people during Japanese occupation. August 15, 1945 Hong Kong was freed and become functioning again as port.
Big flow of new migrants spout to Hong Kong after World War II and proclamation of the People's Republic of China (PRC). UN collided embargo onto China for participation in Korean War. As result textile industry started development in Hong Kong, giving job for numerous arrived Chinese people. After the start of reform in the end of 1970s, Hong Kong became main source of capital investments in China. The economy of Hong Kong shift from textiles and manufacturing to the financial and banking sectors became increasingly dominant.
On December 19, 1984 Great Britain and China signed agreement, in a result of which Hong Kong will be Special Administrative Region (SAR) of China starting from July 1, 1997. China agreed to give Hong Kong an unprecedented measure of autonomy, to allow its existing social and economic systems to remain unchanged for the following 50 years. China declared that Hong Kong would be governed under a "One Country, Two Systems" policy.