The history of North Korea began with the partition of Korea (smell) at the end of World War II in 1945, and the creation of the Communist-aligned Democratic People's Republic of Korea (DPRK) headed by the former guerrilla leader, Kim Il-sung. In 1950 the Korean War broke out. After much destruction, the war ended with the status quo being restored. The DPRK had failed to unify Korea under its leadership, and the US-led United Nations force had failed to conquer North Korea. The peninsula was divided by the Korean Demilitarized Zone, and a US military force remained in South Korea.
Tension between the two sides continued. Kim Il-sung remained in power until his death in 1994. He developed a pervasive personality cult and steered the country on an independent course in accordance with the principle of Juche (or self-reliance). However, with natural disasters and the collapse of the Soviet Bloc in 1991, North Korea went into a severe economic crisis. Kim Il-sung's son, Kim Jong-il, succeeded him, and was in turn succeeded by his son, Kim Jong-un. Amid international alarm, North Korea developed nuclear missiles.
From 1910 to the end of World War II, Korea was under Japanese rule. Most Koreans were peasants engaged in subsistence farming. In the 1930s, Japan developed mines, hydro-electric dams, steel mills, and manufacturing plants in northern Korea and neighboring Manchuria. The Korean industrial working class expanded rapidly, and many Koreans went to work in Manchuria. As a result, 65% of Korea's heavy industry was located in the north, but, due to the harshness of the terrain, only 37% of its agriculture.
A Korean guerrilla movement emerged in the mountainous interior and in Manchuria, harassing the Japanese imperial authorities. One of the most prominent guerrilla leaders was the Communist Kim Il-sung.