The Royal Navy launched the first all-aircraft ship-to-ship naval attack in history, employing 21 Fairey Swordfish biplane torpedo bombers from the aircraft carrier HMS Illustrious in the Mediterranean Sea.

The attack struck the battle fleet of the Regia Marina at anchor in the harbour of Taranto, using aerial torpedoes despite the shallowness of the water.

According to Admiral Cunningham, "Taranto, and the night of 11–12 November 1940, should be remembered forever as having shown once and for all that in the Fleet Air Arm the Navy has its most devastating weapon.

"[1] Since long before the First World War, the Italian Regia Marina's First Squadron had been based at Taranto, a port-city on Italy's south-east coast.

After Italy's entry into World War II in 1940, British and Italian forces in North Africa engaged each other in the Western Desert Campaign.

Instead, British ships steamed around the Cape of Good Hope, up the east coast of Africa, and then through the Suez Canal to reach Alexandria.

Following the concept of a fleet in being, the Italians usually kept their warships in harbour and were unwilling to seek battle with the Royal Navy on their own, also because any ship lost larger than a destroyer could not be replaced.

The older carrier, HMS Eagle, on Cunningham's strength, was ideal, possessing a very experienced air group composed entirely of the obsolescent Swordfish aircraft.

[2] It was originally scheduled to take place on 21 October 1940, Trafalgar Day, but a fire in an auxiliary fuel tank of one Swordfish led to a delay.

The small number of attacking warplanes raised concern that Judgment would only alert and enrage the Italian Navy without achieving any significant results.

These flights produced photos on which the intelligence officer of Illustrious spotted previously unexpected barrage balloons; the attack plan was changed accordingly.

[2] To make sure the Italian warships had not sortied, the British also sent over a Short Sunderland flying boat on the night of 11 November, just as the carrier task force was forming up off the Greek island of Cephalonia, about 170 nmi (310 km; 200 mi) from Taranto harbour.

The next three aircraft, led by Lieutenant Commander K Williamson RN of 815 Squadron, attacked over San Pietro Island, and struck the battleship Conte di Cavour with a torpedo that blasted a 27 ft (8.2 m) hole in her side below her waterline.

[10] The two remaining aircraft in this sub-flight continued, dodging barrage balloons and receiving heavy anti-aircraft fire from the Italian warships and shore batteries, to press home an unsuccessful attack on the battleship Andrea Doria.

The final aircraft to arrive on the scene 15 minutes behind the others made an unsuccessful dive-bombing attack on one of the Italian cruisers despite heavy anti-aircraft fire, then safely returned to Illustrious, landing at 02:39.

Just past midnight, they met and destroyed four Italian merchantmen (Capo Vado, Catalani, Locatelli and Premuda), damaging the torpedo-boat Nicola Fabrizi, while the heavily out-gunned auxiliary cruiser Ramb III fled.

[13] Cunningham and Lyster wanted to strike Taranto again the next night with Swordfish (six torpedo-bombers, seven bombers, and two flare-dispensers) – one wag in the pilots' room remarked, "They only asked the Light Brigade to do it once!

[13] The Italian fleet lost half of its capital ships in one night; the next day, the Regia Marina transferred its undamaged ships from Taranto to Naples to protect them from similar attacks,[4] until the defences at Taranto (mainly the anti-torpedo nets) were brought up to adequate levels to protect them from further attacks of the same kind (which happened between March and May 1941).

[17] Cunningham wrote after the attack: "The Taranto show has freed up our hands considerably & I hope now to shake these damned Eyeties up a bit.

Only five days after Taranto, Campioni sortied with two battleships, six cruisers and 14 destroyers to successfully disrupt a mission to deliver aircraft to Malta.

Japanese Lieutenant Commander Takeshi Naito, the assistant naval attaché to Berlin, flew to Taranto to investigate the attack firsthand.

[24] However, the Japanese had been working on shallow-water solutions since early 1939, with various shallow ports as the notional targets, including Manila, Singapore, Vladivostok, and Pearl Harbor.

[25] In the early 1930s, as their Type 91 aerial torpedo entered service, the Japanese used a breakaway wooden nose to soften its impact with the water.

Battleships were found to be less useful in the expanses of the Pacific than in the confines of the Mediterranean; the older ships were too slow to escort the carriers and were chiefly used as fire support for amphibious operations.