Canadian, British, and Polish forces pressed a brutal amphibious and infantry campaign through the flooded lowlands of the Scheldt estuary in the Netherlands, fighting to clear German defenders and open shipping access to the port of Antwerp. Waged in freezing mud and deliberately flooded polders, the five-week battle cost the First Canadian Army over 12,000 casualties but finally secured the Allies' most crucial supply artery in northwest Europe.
Antwerp's port facilities had fallen into Allied hands nearly undamaged in early September, a huge prize, but the Germans still controlled the sixty-mile Scheldt estuary connecting the port to the North Sea, rendering the harbor useless. General Eisenhower's failure to prioritize clearing the estuary immediately after Antwerp's capture is considered one of the costliest strategic delays of the campaign in northwest Europe, giving German General Gustav von Zangen weeks to fortify the approaches.
Canadian and Polish troops, later joined by British forces, waded through deliberately flooded polder land on the Beveland peninsula and Walcheren island, fighting in conditions that soldiers compared to Flanders fields of the previous war: waist-deep water, mud that swallowed vehicles, and German positions dug into dikes with commanding fields of fire.
By early November, the Allies finally secured the estuary, but the delay meant Antwerp's port did not open for cargo until the end of November, a lag that arguably prolonged the war by weeks by starving Allied forces of supplies during the critical autumn push toward Germany, and directly contributed to the German ability to mass forces for the Ardennes offensive weeks later.