Wilson was appointed to lead a Commonwealth expeditionary force ("W Force") of two infantry divisions and an armoured brigade to help Greece resist Italy and the subsequent German invasion in April 1941. Although the Allied forces were hopelessly inadequate Churchill's War Cabinet had thought it important to provide support for the only country outside the Commonwealth which was resisting the Axis advance. Wilson completed the evacuation of British troops from Greece on 29 April 1941. He was appointed a GBE on 4 March 1941 and promoted to full general on 31 May 1941.