Roughly 6,000 Allied troops, mostly Canadian, assaulted the Nazi-occupied port of Dieppe on the French coast in a large-scale raid intended to test German coastal defenses. The operation collapsed within hours; nearly 60 percent of the attacking force was killed, wounded, or captured. The catastrophic losses provided grim but valuable lessons later applied to the D-Day landings.
Operation Jubilee was meant to seize and briefly hold a French port, gather intelligence, and demonstrate that a full invasion was feasible, partly to placate Stalin's demands for a second front. Instead, German defenders, well dug into cliffside positions, poured machine-gun and artillery fire onto beaches choked with tanks that could not climb the loose chert shingle.
Of roughly 6,000 men who landed, mostly Canadians alongside British commandos and a handful of American Rangers, more than 3,600 were killed, wounded, or taken prisoner in under ten hours. Canadian war planners were haunted by the raid for years. Yet planners for Operation Overlord in 1944 studied Dieppe intensely, drawing lessons about the need for overwhelming naval and air bombardment, specialized armor, and avoiding fortified ports altogether in favor of open beaches.
Key people: John Hamilton Roberts, Lord Lovat