In March he returned to England and was promoted again, this time to command of the Canadian First Army. Although it was designated as the Canadian First Army, it contained a significant amount of British and Polish troops, including the entire British I Corps, commanded by Lieutenant-General John Crocker, along with the Polish 1st Armoured Division, and other troops from various European countries. The First Army was withheld by General Sir Bernard Montgomery, commander of the 21st Army Group, during the first few weeks of the Normandy Campaign.