The Battle of Chosin Reservoir (17 November – 13 December 1950) was an important battle during the Korean War.

The United Nations Command, led by the United States, occupied North Korea, which had attacked South Korea.

The People's Republic of China entered the war after it had given several warnings to the United Nations. It attacked United Nations Command and forced its retreat.

The result was a stalemate, with an armistice dividing Korea at the 38th parallel.