On 6 September 1944, the 2nd Canadian Division occupied Dunkirk, the site where 338,226 British, French, and Belgian soldiers were evacuated from France on 4 June 1940. The following day, 7 September 1944, the 2nd Canadian Division and 4th Canadian Armoured Division crossed the French border into Belgium. The 2nd Canadian Division entered the Belgian port city of Ostend.
The major task for the 1st Canadian Army throughout September was the clearing of the channel port areas of France and Belgium. The 1st British Corps invested Le Havre on 10 and 11 September. The 3rd Canadian Division reduced isolated pockets of German resistance in the French ports of Boulogne (22 September), Cap Gris Nez (29 September), and Calais (1 October). At this time, the ever-lengthening supply lines extending from the improvised harbours in Normandy were limiting the whole campaign. While the capture of these smaller ports helped to relieve the supply situation facing the Allied armies, only the opening up of the port of Antwerp would resolve the problem. On 4 September, British troops captured the port with its harbour facilities intact, but the German army still had to be cleared from the banks of the lower Scheldt River. If allowed to remain there, the German troops would block the shipping lanes to Antwerp. The British, Polish, and Canadian soldiers of the 1st Canadian Army, along with their counterparts in the 104th U.S. Infantry Division, were assigned the critical task of clearing the area. The commander of the American division, Major-General Terry Allen, had commanded the 1st U.S. Infantry Division when it fought alongside the 1st Canadian Division in Sicily.