The attack started at 21:00, 11 November 1940, when the first of two waves of Fairey Swordfish torpedo bombers took off from "Illustrious", followed by the second wave an hour later. The attack was a great success: the Italian fleet lost half its strength in one night. The "fleet-in-being" diminished in importance and the threat to the Royal Navy's control of the Mediterranean had been considerably reduced. Cunningham said of the victory: "Taranto, and the night of 11–12 November 1940, should be remembered for ever as having shown once and for all that in the Fleet Air Arm the Navy has its most devastating weapon." The Royal Navy had launched the first all-aircraft naval attack in history, flying a small number of aircraft from an aircraft carrier. This, and other aspects of the raid, were important facts in the planning of the Japanese attack on Pearl Harbor in 1941: the Japanese planning staff were thought to have studied it intensively.