The COSSAC staff planned to begin the invasion on 1 May 1944. The initial 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 (SHAEF). General Bernard Montgomery was named commander of the 21st Army Group, which comprised all of the land forces involved in the invasion. On 31 December 1943, Eisenhower and Montgomery first saw the COSSAC plan, which proposed amphibious landings by three divisions, with two more divisions in support. The two generals immediately insisted on expanding the scale of the initial invasion to five divisions, with airborne descents by three additional divisions, to allow operations on a wider front and to speed up the capture of the port at Cherbourg. The need to acquire or produce extra landing craft for the expanded operation meant delaying the invasion until June 1944. Eventually the Allies committed 39 divisions to the Battle of Normandy: 22 American, 12 British, three Canadian, one Polish, and one French, totalling over a million troops all under overall British command.