After World War II ended in 1945, the Korean Peninsula became divided. In the North, the Communists announced the formation of the Democratic People's Republic of Korea on September 9th, 1948. Kim Il-sung became North Korea's leader, and claimed to rule the whole peninsula.

North Korean troops invaded the South in June 1950, beginning the Korean War. Fighting continued until July 1953, with neither side winning. The war involved not only the two Koreas, but also the most powerful Communist and non-Communist nations. The non-Communist nations fought under UN supervision.

After 1953 and 1956, Kim Il-sung's government organized farmland into collective farms, and built up heavy industry and military power. Kim's government operated as a strict dictatorship. Under Kim's government, the country began experiencing food shortages in the mid-1990's. Kim remained in power until his death in 1994. In 1998, the government proclaimed him "eternal president."

Kim Jong-il, Kim Il-sung's son, became North Korea's leader in 1998. In 2000, he and the South Korean President Kim Dae-jung met in an effort to improve relations between the two countries. Their meeting marked the first time that leaders from both nations had met since the split of Korea into two countries.

Despite North Korea's 1994 agreement with the United States to not develop nuclear weapons, a crisis developed in 2002 when North Korea revealed its secret nuclear ambitions. In 2006, the nation claimed to have tested a nuclear weapon. In 2007 in exchange for fuel and other aid, North Korea shut down its main nuclear reactor and began disabling its nuclear weapons program.