Following the end of the colonial rule by the Japanese Empire, Korea split into two; the North and the South. This was after the conclusion of World War II in 1945. At the time, the US and the Soviet Union occupied a section of the island. The border of these zones was located along the 38Th parallel.
However, the US and the Soviet Union were unable to reach an agreement over unifying the North and the South. This was mainly due to the looming Cold War between the two superpowers. In 194, South Korea, which was occupied by the US, conducted its first post-war elections. The elections were overseen by the United Nations. Syngman Rhee, an outspoken anti-communist, emerged victorious in the polls. On the other hand, Joseph Stalin, the then ruler of the Soviet Union, appointed Kim Il-sung as the leader of North Korea.
The appointment of the two leaders for the North and South resulted in the formation of the Democratic People’s Republic of Korea and the Republic of Korea, respectively. The South was backed by the US, while the North was supported by the Soviet Union. Both governments claimed the authority over the entire Korean peninsula. As a result, the Korean War started, lasting for three years until 1953. Due to the absence of an outright winner, the two countries established the Korean Demilitarized Zone which acts as the boundary between them. This zone exists to date.