The former British colony became a special administrative region of China in 1997, when Britain's 99-year lease of the New Territories, north of Hong Kong island, expired.
Hong Kong is governed under the principle of "one country, two systems", under which China has agreed to give the region a high degree of autonomy and to preserve its economic and social systems for 50 years from the date of the handover.
But Beijing can veto changes to the political system, and pro-democracy forces have been frustrated by what they see as the slow pace of political reform.
HONG KONG SPECIAL ADMINISTRATIVE REGION OF THE PEOPLE'S REPUBLIC OF CHINA: FACTS
Administrative centre: Tamar
Area: 2,755 sq km
Languages: Chinese, English
Population: 7.2 million
Life expectancy: 82 years (men) 88 years (women)
Chief executive: John Lee Ka-chiu
As the sole candidate approved by China in the 2022 Hong Kong Chief Executive election, John Lee took office in July 2022.
Originally a police officer, Lee served as the deputy commissioner of the Hong Kong Police Force from 2010 to 2012. Lee is known as being a hardliner against the pro-democracy camp in Hong Kong, having played a key role in the crackdown of the opposition.
His selection has been seen as a move by Beijing to further integrate Hong Kong with the mainland.
Hong Kong is home to many of Asia's biggest media players. It has a major film industry and is a centre for broadcasting and publishing.
The territory has kept its editorially-dynamic media, in contrast to the rest of China. But media watchdogs have flagged up concerns about growing mainland influence.
Some key dates in Hong Kong's history:
214BC - Qin dynasty incorporates Hong Kong into China.
1513AD - Portuguese explorer Jorge Álvares is the earliest European visitor. Portuguese merchants establish before being expelled after military clashes in the 1520s.
c. 1549 - Portuguese-Chinese trade relations are re-established. Portugal acquires a permanent lease for Macau in 1557.
1757 - Qing authorities establish the Canton System to regulate foreign trade more strictly. To pay for Chinese commodities like tea, silk and porcelain, British traders sell large amounts of Indian opium to China. Faced with a drug crisis, Qing officials take ever more aggressive actions to halt the opium trade.
1839 - China rejects proposals to legalise and tax opium, destroys opium stockpiles and halts foreign trade, triggering a British military response and the First Opium War.
1841 - China is defeated and cedes Hong Kong Island to Britain. Fighting continues for another year before the 1842 Treaty of Nanking.
1856-60 - Second Opium War sees China cede more territory in the Hong Kong area to Britain.
1898 - China leases the New Territories together with 235 islands to Britain for 99 years.
1941-45 - Japan occupies Hong Kong during World War Two.
1950s - Hong Kong enjoys economic revival based on light industries such as textiles.
1956 - The Double Ten riots due to escalating provocations between Nationalist and Communist groups on Kowloon sees 59 people killed.
1967 - Large-scale anti-government riots partially inspired by earlier successful anti-colonial demonstrations in Portuguese Macau. More than 50 people are killed.
1970s - Hong Kong is established as an "Asian Tiger" - one of the region's economic powerhouses - with a thriving economy based on high-technology industries.
1997 - Hong Kong is handed back to the Chinese authorities after more than 150 years of British control.
2009 - Tens of thousands of people attend a vigil in Hong Kong on the 20th anniversary of the Tiananmen Square massacre. The territory is the only part of China to mark the anniversary.
2014 - Pro-democracy demonstrators occupy the city centre for weeks in protest at the Chinese government's decision to limit voters' choices in the 2017 Hong Kong leadership election. More than 100,000 people took to the streets at the height of the Occupy Central protests.
2017 - Chinese President Xi Jinping visits Hong Kong to swear in Chief Executive Carrie Lam, and uses his visit to warn against any attempt to undermine China's influence over the special administrative region.
2019 - Hong Kong sees anti-government and pro-democracy protests, involving violent clashes with police, against a proposal to allow extradition to mainland China.
2021 - Beijing amends Hong Kong's electoral system, reducing the number of directly elected seats in the Legislative Council and requiring all candidates be vetted and approved by a Beijing-appointed committee.