During the Second World War, I Corps' first assignment was again to the British Expeditionary Force (BEF) where it was commanded by General Sir John Dill, and then Lieutenant General Michael Barker from April 1940. After the Germans broke through Allied lines in the Battle of France in May 1940, the BEF was forced to retreat to Dunkirk for evacuation to England. The Commander-in-Chief (C-in-C) of the BEF, General Lord Gort, ordered Barker to form the rearguard with I Corps to cover the evacuation, and surrender to the Germans as a last resort. However, the acting commander of II Corps, Major General Bernard Montgomery, advised Gort that Barker was in an unfit state to be left in final command, and recommended that Major General Harold Alexander of the 1st Division should be put in charge. Gort did as Montgomery advised, and in the event the bulk of I Corps was successfully evacuated. As Montgomery recalled: '"Alex" got everyone away in his own calm and confident manner'.