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
Following the surrender of Japan, in 1945, the "Republic of Korea" (/, IPA: , ; ) was adopted as the legal English name for the new country. Since the government only controlled the southern part of the Korean Peninsula, the informal term "South Korea" was coined, becoming increasingly common in the Western world. While South Koreans use "Han" (or "Hanguk") to refer to the entire country, North Koreans and ethnic Koreans living in China and Japan use the term "Joseon" as the name of the country. The Korean name "Daehan Minguk" is sometimes used by South Koreans as a metonym to refer to the Korean ethnicity (or "race") as a whole, rather than just the South Korean state.