Although the threat from the French Fleet had been neutralised, Cunningham was still aware of the threat posed by the Italian Fleet to British North African operations, based in Egypt.
Although the Royal Navy had won in several actions in the Mediterranean, considerably upsetting the balance of power, the Italians who were following the theory of a fleet in being had left their ships in harbour.
This made the threat of a sortie against the British Fleet a serious problem.
At the time the harbour at Taranto contained six battleships (five of them battle-worthy), seven heavy cruisers, two light cruisers, and eight destroyers.
The Admiralty, concerned with the potential for an attack, had drawn up Operation Judgement; a surprise attack on Taranto Harbour.
To carry out the attack, the Admiralty sent the new aircraft carrier HMS Illustrious, commanded by Lumley Lyster, to join HMS Eagle in Cunningham's fleet.

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.

Cunningham's official reaction at the time was memorably terse.
After landing the last of the attacking aircraft, Illustrious signalled "Operation Judgement executed".
After seeing aerial reconnaissance photographs the next day which showed several Italian ships sunk or out of action, Cunningham replied with the two-letter code group which signified, "Manoeuvre well executed".
Although the threat from the French Fleet had been neutralised, Cunningham was still aware of the threat posed by the Italian Fleet to British North African operations, based in Egypt. Although the Royal Navy had won in several actions in the Mediterranean, considerably upsetting the balance of power, the Italians who were following the theory of a fleet in being had left their ships in harbour. This made the threat of a sortie against the British Fleet a serious problem. At the time the harbour at Taranto contained six battleships (five of them battle-worthy), seven heavy cruisers, two light cruisers, and eight destroyers. The Admiralty, concerned with the potential for an attack, had drawn up Operation Judgement; a surprise attack on Taranto Harbour. To carry out the attack, the Admiralty sent the new aircraft carrier HMS Illustrious, commanded by Lumley Lyster, to join HMS Eagle in Cunningham's fleet.
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.
Cunningham's official reaction at the time was memorably terse. After landing the last of the attacking aircraft, Illustrious signalled "Operation Judgement executed". After seeing aerial reconnaissance photographs the next day which showed several Italian ships sunk or out of action, Cunningham replied with the two-letter code group which signified, "Manoeuvre well executed".
Andrew Cunningham, 1st Viscount Cunningham of Hyndhope