History of Korea
After the end of WWII in 1945, the Allies divided the country into a northern area (protected by the Soviets) and a southern area protected (primarily by the United States). In 1948, when the powers failed to agree on the formation of a single government, this partition became the modern states of North and South Korea. The peninsula was divided at the 38th Parallel: the "Republic of Korea" was created in the south, with the backing of the US and Western Europe, and the "Democratic People's Republic of Korea" in the north, with the backing of the Soviets and the communist People's Republic of China. The new premier of North Korea, Kim il-Sung, launched the Korean War in 1950 in an attempt to reunify the country under Communist rule. After immense material and human destruction, the conflict ended with a cease-fire in 1953. The two nations officially remain at war because a peace treaty was never signed. In 1991, both states were accepted into the United Nations.
South Korea
The history of Korea begins with the founding of Joseon (also known as "Gojoseon", or Old Joseon, to differentiate it with the 14th century dynasty) in 2333 BCE by Dangun, according to Korea's foundation mythology. Gojoseon expanded until it controlled the northern Korean Peninsula and parts of Manchuria. Gija Joseon was purportedly founded in the 12th century BC, but its existence and role have been controversial in the modern era. In 108 BCE, the Han dynasty defeated Wiman Joseon and installed four commanderies in the northern Korean peninsula. Three of the commanderies fell or retreated westward within a few decades. As Lelang commandery was destroyed and rebuilt around this time, the place gradually moved toward Liaodong. Thus, its force was diminished and it only served as a trade center until it was conquered by Goguryeo in 313.