D-Day was the largest seaborne invasion in history, marking the start of the liberation of Western Europe from Nazi control. Codenamed Operation Overlord, the Allied forces (primarily American, British, and Canadian) landed on five beaches in Normandy: Utah, Omaha, Gold, Juno, and Sword. To ensure success, the Allies used a massive deception campaign (Operation Fortitude) to convince Hitler that the invasion would happen at Pas-de-Calais. General Dwight D. Eisenhower commanded the operation, which involved 156,000 troops, 7,000 ships, and 11,000 aircraft. Despite heavy casualties—especially at Omaha Beach—the Allies established a beachhead, allowing for the steady buildup of troops that would eventually break through German lines and liberate Paris by August 1944.