On 25 June 1950, North Korean forces invaded South Korea in an effort to unify both countries under the northern communist government. A United Nations military force composed of seventeen nations under the command of American general Douglas MacArthur, soon began to arrive in theatre. France joined the U.N. forces in a 23 August decision, this force, composed of a battalion of 1,051 volunteers, both reservists and members of the regular force from the three services, set sail from Marseille on 25 October 1950. This battalion was under the command of general Raoul Magrin-Vernerey, who accepted a temporary demotion to lieutenant-colonel for the chance and honour to command this unit in Korea.