Who commanded the UN forces in Korea until he was relieved in 1951?

Douglas MacArthur commanded the United Nations forces in Korea until President Harry Truman relieved him in April 1951. MacArthur was appointed commander of the United Nations Command after North Korea invaded South Korea on June 25, 1950.

He became famous for conceiving and directing the daring Inchon landing, formally known as Operation Chromite, which helped UN forces break out of the Pusan Perimeter and recapture Seoul. His subsequent advance into North Korea, however, brought Chinese forces into the war after they crossed the Yalu River in late 1950. A series of Chinese offensives pushed UN forces southward again.

MacArthur's removal was a civil-military dispute, not a battlefield promotion. He publicly challenged Truman administration policy, especially its limits on expanding the war against China. Truman relieved him of command on April 11, 1951, replacing him with General Matthew Ridgway. MacArthur returned to the United States and addressed Congress soon afterward.