Summary: In late 1941, amidst World War II, Italy launched a daring operation against the British Royal Navy in Alexandria Harbor, utilizing a specialized unit called Decima Flottiglia MAS (X MAS) equipped with "human torpedoes" or mini-subs. The operation aimed to undermine British naval supremacy in the Mediterranean, exacerbated by earlier naval losses and anticipation of conflicts with Japan. The Italians, drawing on World War I tactics, targeted the battleships HMS Queen Elizabeth and HMS Valiant, placing limpet mines that inflicted severe damage, sinking Queen Elizabeth into the mud and seriously damaging Valiant. This audacious attack temporarily removed two central British naval units from the Mediterranean at minimal cost to Italy. The captured Italian commandos, showing remarkable resilience and silence under captivity, were eventually released and some even served in post-war Italy. This episode highlighted the strategic impact special operations forces could have, influencing future military strategies and special operations doctrines in the United States and Soviet Union.

The Underwater Assault on HMS Queen Elizabeth and Valiant

Mussolini’s effort to seize control of the Mediterranean had, by late 1941, largely ended in failure. The success of the Royal Navy in the raid on Taranto and at the Battle of Cape Matapan had given the British a decisive advantage. Low morale and fuel shortages further limited the effectiveness of the Regia Marina. Yet the Italians still had several modern battleships, along with a few older, modernized vessels. And on the upside, the Royal Navy had lost one of its battleships, HMS Barham, to U-boat attack in late November. In anticipation of war with Japan, additional Royal navy warships were headed to the Far East.

That’s when the Italians decided to get creative. In order to further redress the imbalance, the Italians conceived a daring operation to attack British ships directly. They borrowed a page from their own history in World War I, and managed to knock two British battleships out of the war.

The Plan: 

Italy lacked aircraft carriers, and consequently could not respond in kind to the Taranto attack. But in a previous war, the Italians had developed a weapon that could be just as lethal to battleships as the torpedo bomber. In 1918, days before the surrender of the Central Powers, the collapsing government of Austria-Hungary made clear that it would pass one of its dreadnought battleships, SMS Viribus Unitis, on to the newly created State of Slovenes, Croats, and Serbs, a forerunner of Yugoslavia. Italy believed the ship still to be in the possession of Austria-Hungary, and no peace treaty yet existed. In any case, the Italians had little interest in seeing a battleship pass into the possession of what might become a regional rival. Accordingly, a team of divers entered Pula Harbor and attached a mine to the bottom of the battleship. They were quickly captured, and confessed to attaching the weapon without indicating the exact spot of its placement. But the Austrians couldn’t find the mine, which exploded and sank the battleship.

In the late 1930s, the Italians began to assemble a team that would become the scourge of the Mediterranean. Based on experience in the Pula raid and the more recent enthusiasm for spearfishing and underwater diving, Italy began to develop a capability for attacking enemy ships at anchor. This included explosive motorboats, diving equipment, limpet mines, and two-man minisubs known as “human torpedoes.” In 1940, the Regia Marina stood up Decima Flottiglia MAS, a team detailed to conduct raids against Allied facilities.

From the beginning of the war, X MAS (from the Roman number for ten) undertook mischief across the Mediterranean. The raids were dangerous, and depended on a good deal of luck to succeed. Nevertheless, teams managed to cause significant damage in several different ports. Like many special forces units, X MAS was also known for its ideological enthusiasm, in this case fanatic support for the Fascist government of Italy. 

The Attack: 

Scire, a submarine carrying three minisubs, left Italy on December 3. A short while later, Scire picked up six members of X MAS, who would form into three teams of two. On December 19, the attack commenced, with Scire making a submerged approach to Alexandria Harbor. The three torpedoes were released, and Scire retreated an appropriate distance. Their targets were two battleships, the HMS Queen Elizabeth and HMS Valiant, and an aircraft carrier that was expected to be in port but was absent. After placing limpet mines, the teams would exfiltrate into Alexandria, then make their way to a pre-arranged point where Scire would pick them up with small boats.

Both Queen Elizabeth and Valiant had recently been modernized, bringing them up to the standard of modern battleships. They constituted the core of the British Mediterranean Fleet, especially with more modern units transferred to the Far East. One team successfully attached a mine to the hull of Queen Elizabeth and another team to a large oil tanker (an aircraft carrier could not be found). 

The final team second ran into mechanical problems, both with its breathing equipment and with the torpedo. The two frogmen nevertheless managed to attach a bomb to HMS Valiant, although both members of the team were captured in the process. A scene played out aboard Valiant reminiscent of what had happened in Pola twenty-three years before. The captain of Valiant ordered the Italians confined below decks, where they would be vulnerable to the explosion. Nevertheless, they remained silent until just before the mine exploded.

The mines inflicted severe damage. Queen Elizabeth sank into the mud, although she, fortunately, remained upright. Valiant was seriously damaged but did not come to rest on the floor of the harbor. The tanker Sagona was badly damaged, and in the process of her sinking, a British destroyer also suffered serious damage. The British took elaborate steps to hide evidence of the damage, but Queen Elizabeth took nine months to repair, Valiant six. At a stroke, the Italians had eliminated two of the Royal Navy’s most powerful units from the Mediterranean, at very little cost to themselves. The other four commandos were arrested in the vicinity of Alexandria. 

Parting Thoughts:

By the time the two battleships re-entered service, the balance had tilted decisively in favor of the Allies. Valiant and Queen Elizabeth served for most of the rest of the war in the Pacific, although Valiant fell victim to a dreadful accident in a floating drydock that severely damaged the ship and removed her from active service.

The attack was dramatized in two British and one Italian films. Most of the captured divers were released from custody in 1944, after having decided to fight for the Allied Italian government. Several were active in the post-war Italian Navy, and two of them served in the Italian parliament. The raid helped demonstrate the potential for special operations forces to have a strategic impact, and influenced how both the United States and the Soviet Union thought about special operators after the war.

About the Author: Dr. Robert Farley 

Dr. Robert Farley, a frequent contributor to TNI, teaches at the Patterson School of Diplomacy and International Commerce at the University of Kentucky. He is the author of the Battleship Book and can be found at @drfarls. This first appeared in 2019.