The Qin dynasty incorporated the Hong Kong area into China for the first time in 214 BCE, after conquering the indigenous Baiyue.[33] The region was consolidated under the Nanyue kingdom (a predecessor state of Vietnam) after the Qin collapse[34] and recaptured by China after the Han conquest.[35] During the Mongol conquest of China in the 13th century, the Southern Song court was briefly located in modern-day Kowloon City (the Sung Wong Toi site) before its final defeat in the 1279 Battle of Yamen by the Yuan Dynasty.[36] By the end of the Yuan dynasty, seven large families had settled in the region and owned most of the land. Settlers from nearby provinces migrated to Kowloon throughout the Ming dynasty.[37] The earliest known European visitor was Portuguese explorer Jorge Álvares, who arrived in 1513.[38][39] Portuguese merchants established a trading post called Tamão in Hong Kong waters and began regular trade with southern China. Although the traders were expelled after military clashes in the 1520s,[40] Portuguese-Chinese trade relations were re-established by 1549. Portugal acquired a permanent lease for Macau in 1887.[41] After the Qing conquest, maritime trade was banned under the Haijin policies. From 1661 to 1683, the population of most of the area forming present day Hong Kong was cleared under the Great Clearance, turning the region into a wasteland.[42] The Kangxi Emperor lifted the maritime trade prohibition, allowing foreigners to enter Chinese ports in 1684.[43] Qing authorities established the Canton System in 1757 to regulate trade more strictly, restricting non-Russian ships to the port of Canton.[44] Although European demand for Chinese commodities like tea, silk, and porcelain was high, Chinese interest in European manufactured goods was insignificant, so that Chinese goods could only be bought with precious metals. To reduce the trade imbalance, the British sold large amounts of Indian opium to China. Faced with a drug crisis, Qing officials pursued ever more aggressive actions to halt the opium trade.[45] British colony Main article: British Hong Kong Hong Kong in 1868, photograph by John Thomson In 1839, the Daoguang Emperor rejected proposals to legalise and tax opium and ordered imperial commissioner Lin Zexu to eradicate the opium trade. The commissioner destroyed opium stockpiles and halted all foreign trade,[46] triggering a British military response and the First Opium War. The Qing surrendered early in the war and ceded Hong Kong Island in the Convention of Chuenpi. British forces began controlling Hong Kong shortly after the signing of the convention, from 26 January 1841.[47] However, both countries were dissatisfied and did not ratify the agreement.[48] After more than a year of further hostilities, Hong Kong Island was formally ceded to the United Kingdom in the 1842 Treaty of Nanking.[49] Administrative infrastructure was quickly built by early 1842, but piracy, disease, and hostile Qing policies initially prevented the government from attracting commerce. Conditions on the island improved during the Taiping Rebellion in the 1850s, when many Chinese refugees, including wealthy merchants, fled mainland turbulence and settled in the colony.[17] Further tensions between the British and Qing over the opium trade escalated into the Second Opium War. The Qing were again defeated and forced to give up Kowloon Peninsula and Stonecutters Island in the Convention of Peking.[50] By the end of this war, Hong Kong had evolved from a transient colonial outpost into a major entrepôt. Rapid economic improvement during the 1850s attracted foreign investment, as potential stakeholders became more confident in Hong Kong's future.[51] The colony was further expanded in 1898 when the United Kingdom obtained a 99-year lease of the New Territories.[52] The University of Hong Kong was established in 1911 as the territory's first institution of higher education.[53] Kai Tak Airport began operation in 1924, and the colony avoided a prolonged economic downturn after the 1925–26 Canton–Hong Kong strike.[54][55] At the start of the Second Sino-Japanese War in 1937, Governor Geoffry Northcote declared Hong Kong a neutral zone to safeguard its status as a free port.[56] The colonial government prepared for a possible attack, evacuating all British women and children in 1940.[57] The Imperial Japanese Army attacked Hong Kong on 8 December 1941, the same morning as its attack on Pearl Harbor.[58] Hong Kong was occupied by Japan for almost four years before the British resumed control on 30 August 1945.[59] The flag of British Hong Kong from 1959 to 1997 Peking Road in Tsim Sha Tsui in 1971 Its population rebounded quickly after the war, as skilled Chinese migrants fled from the Chinese Civil War and more refugees crossed the border when the Chinese Communist Party took control of mainland China in 1949.[60] Hong Kong became the first of the Four Asian Tiger economies to industrialise during the 1950s.[61] With a rapidly increasing population, the colonial government attempted reforms to improve infrastructure and public services. The public-housing estate programme, Independent Commission Against Corruption, and Mass Transit Railway were all established during the post-war decades to provide safer housing, integrity in the civil service, and more reliable transportation.[62][63] Nevertheless, widespread public discontent resulted in multiple protests from the 1950s to 1980s, including pro-Republic of China and pro-Chinese Communist Party protests. In the 1967 Hong Kong riots, pro-PRC protestors clashed with the British colonial government. As many as 51 were killed and 802 were injured in the violence, including dozens killed by the Royal Hong Kong Police via beatings and shootings.[64] Although the territory's competitiveness in manufacturing gradually declined because of rising labour and property costs, it transitioned to a service-based economy. By the early 1990s, Hong Kong had established itself as a global financial centre and shipping hub.[65] Chinese special administrative region Further information: Handover of Hong Kong Victoria Harbour and Hong Kong Island, 2007 The colony faced an uncertain future as the end of the New Territories lease approached, and Governor Murray MacLehose raised the question of Hong Kong's status with Deng Xiaoping in 1979.[66] Diplomatic negotiations with China resulted in the 1984 Sino-British Joint Declaration, in which the United Kingdom agreed to the handover of the colony in 1997 and China would guarantee Hong Kong's economic and political systems for 50 years after the handover.[67] The impending handover triggered a wave of mass emigration as residents feared an erosion of civil rights, the rule of law, and quality of life.