The Korean War: Key Events 1950–1953

The Korean War saw dramatic shifts in fortune as the front line surged back and forth across the peninsula. This lesson covers the major phases of the conflict, from the initial North Korean invasion to the armistice of July 1953.

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Phase 1: North Korean Advance (June–September 1950)

The North Korean People's Army (NKPA) launched a devastating invasion on 25 June 1950. The South Korean forces were poorly equipped and quickly overwhelmed.

Event	Date	Detail
North Korean invasion	25 June 1950	75,000 NKPA troops cross the 38th parallel
Seoul falls	28 June 1950	South Korean capital captured within three days
UN Resolution 83	27 June 1950	UN Security Council authorises member states to assist South Korea
Pusan Perimeter	August 1950	UN and South Korean forces pushed back to a small area around Pusan (Busan) in the south-east

By August 1950, the situation was desperate. The UN forces (predominantly American, under the command of General Douglas MacArthur) held only a small pocket around the port of Pusan, known as the Pusan Perimeter.