 After the Germans invaded the Soviet Union in June 1941 , Soviet leader Joseph Stalin began pressing for the creation of a second front in Western Europe . The decision to undertake a cross @-@ channel invasion of continental Europe within the next year was taken at the <unk> Conference , held in Washington in May 1943 . The Allies initially planned to launch the invasion on 1 May 1944 , and a draft of the plan was accepted at the Quebec Conference in August 1943 . General Dwight D. Eisenhower was appointed commander of Supreme Headquarters Allied Expeditionary Force ( <unk> ) . General Bernard Montgomery was named as commander of the 21st Army Group , which comprised all of the land forces involved in the invasion . 
