South Korea country profile
South Korea has developed into one of Asia's most affluent countries since partition in 1948. The Communist North has slipped into totalitarianism and poverty.
The republic was proclaimed in 1948 and received UN-backed support from the US after it was invaded by the North two years later.
The Korean War ended in 1953 without a peace agreement, leaving South Korea technically at war for more than 70 years.
The following four decades were marked by authoritarian rule, during which government-sponsored schemes encouraged the growth of family-owned industrial conglomerates, including the Hyundai and Samsung groups.
They helped transform South Korea into one of the world's major economies and a leading exporter of cars and electronic goods.
The US has tens of thousands of soldiers in the country.
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REPUBLIC OF KOREA: FACTS
Area: 100,363 sq km
Population: 51.8 million
Life expectancy: 80 years (men) 86 years (women)
President: Yoon Suk-yeol
Mr Yoon is a former prosecutor who only entered politics in 2021 and won the 2022 presidential elections by less than 1%.
At his victory ceremony he said he would "pay attention to people's livelihoods, provide warm welfare services to the needy, and make utmost efforts so that our country serves as a proud, responsible member of the international community and the free world".
In foreign policy, he promised a tougher "reset" on relations with China and North Korea and indications of closer ties with the US.
South Korea is a trailblazer for high-speed and wireless internet and nearly every household is connected. Instant messaging and gaming enjoy huge popularity.
South Korean TV soaps are popular across the region, including in China. They are part of the Korean Wave - the export of South Korean popular culture across Asia.
Some key dates in South Korea's history:
1945 - After World War Two, Japanese occupation ends with Soviet troops occupying area north of the 38th parallel, and US troops in the south.
1948 - Republic of Korea proclaimed.
1950 - South declares independence, sparking North Korean invasion.
1953 - Armistice ends Korean War, which has cost two million lives.
1950s - South sustained by crucial US military, economic and political support.
1960s - Major programme of industrial development.
1988 - First free parliamentary elections.
1996 - South Korea admitted to Organisation for Economic Cooperation and Development.
2002 - Battle between South Korean and North Korean naval vessels along their disputed sea border is only one flare-up in the continuiing tension between the two states.
2010 - South Korea breaks off all trade with the North after a naval ship is sunk by a North Korean torpedo.
2012 - South Korea elects its first female president, Park Geun-hye.
2013 - South Korea launches a satellite into orbit for the first time using a rocket launched from its own soil. It comes weeks after a North Korean rocket placed a satellite in orbit.
2018 - North and South Korea agree to march under the same flag at the Winter Olympics in South Korea in a thaw in relations. At a summit meeting in April 2018, President Moon Jae-in and North Korea's Kim Jong-un agree to end hostile actions and work towards reducing nuclear arms on the peninsula.