1) The Korean War began in 1950 when North Korea invaded South Korea, leading the UN to authorize troops to defend South Korea.
2) By 1951, UN forces had driven North Korea back above the 38th parallel but China then entered the war on North Korea's side.
3) Fighting continued until 1953 when an armistice was signed, dividing Korea along the 38th parallel border and establishing a demilitarized zone. Over 2 million military and civilians were killed during the conflict.