The Italian build up at Sidi Barranni was proceeding slowly but steadily, and by early December the Italians would be prepared for a final push into Egypt. The British needed to slow the supplies that were ferried from Italy to North Africa, but the Italian Navy, the Regina Marina, had a significant firepower superiority in the Mediterranean. On the heel of the Italian boot at the naval base of Taranto, the Regina Maria had a fleet of six battleships, sixteen cruisers and thirteen destroyers. The Italian naval threat forced the British Mediterranean Fleet to inefficiently operate en masse against the Italian supply lines linking North Africa and Italy.
On the afternoon of 11 November, 1940, a naval task force under Rear Admiral Lumley Lyster, Britain’s foremost carrier tactician, quietly approached Taranto. Lumley had just one aircraft carrier, and four cruisers and five destroyers. At dusk, Lumley launched his obsolete Swordfish torpedo bombers from the HMS Illustrious. Two hours later around about 10 pm, 21 Swordfish biplanes screamed out of the flare lit darkness, and struck the Italian battleship row. They sunk one battleship, severely damaged two others and damaged two heavy cruisers for the loss of just a single plane. The Raid on Taranto shocked the Italians. In the space of one hour, the Regina Marina went from a dangerous threat to the British Navy in the Mediterranean to a fleet-in-being which would rarely leave port for the rest of the war.
The Japanese naval attaché in Berlin, Lieutenant Commander Takeshi Naito, flew down to Taranto and documented the raid. Naito passed on the information to his friend, carrier pilot Commander Mitsuo Fushida. Fushida went on to plan and lead the aerial attack on Pearl Harbor just over a year later