History of South Korea
The history of South Korea formally begins with its establishment on August 15, 1948.
38th parallel north
Japan had occupied the Korean peninsula between 1910 and 1945. When Japan surrendered in August 1945, the 38th parallel was established as the boundary between Soviet and American occupation zones. This parallel divided the Korean peninsula roughly in the middle. In 1948, this parallel became the boundary between the Democratic People's Republic of Korea (North Korea) and the Republic of Korea (South Korea), both of which claim to be the government of the whole of Korea. On 25 June 1950, after a series of cross-border raids and gunfire from both the Northern and the Southern sides, the North Korean Army crossed the parallel and invaded South Korea. This sparked a United Nations resolution against the aggression and the Korean War, with United Nations troops (mostly Americans) helping to defend South Korea.