'M.41' was an Italian convoy from southern Italy to North Africa (13/16 December 1941).

When Italy declared war on France and the UK on 10 June 1940, its navy was one of the largest in the world, but was restricted to the Mediterranean Sea except for a small force operating from Italian Eritrea and Somaliland into the Red Sea and Gulf of Aden. The British empire possessed enough naval strength and resources to maintain a strong presence in both areas and also to replace most losses by redeploying ships. This persuaded the Italians to exercise extreme caution, a tendency that materialised as a desire to avoid battle except under the most favourable of conditions. The Mediterranean Sea was vital to the interests of both the Italians and British for the movement of men, equipment and supplies: the Italians needed to use convoys for the supply of the Italian (and later German) forces in North Africa, as the British had to maintain the mid-Mediterranean island of Malta as the air and naval base from which the Italian convoy movements cold be interdicted.

The large-scale availability of effective radar and the breaking of Italian codes, most notably those used by Boris Hagelin C38 cipher machine operated by the Italian navy, were major factors in British success.

In November 1941, the supply of the Axis forces in Libya from Italy had been severely interrupted by Commodore W. G. Agnew’s Force 'K', which had destroyed several Italian convoys (most notably the 'Duisburg' convoy) and the loss of nearly 70% of the supplies sent to Libya, this figure including no less than 92% of the fuel being shipped. Force 'K' based at Malta and British warships from Alexandria on the north coast of Egypt, intercepted an Axis convoy based on the ships Maritza and Procida, escorted by two Italian torpedo boats, sailing from Greece to Benghazi on 24 November. The convoy was about 120 miles (190 km) to the west of Crete when the merchant ships were sunk by two British cruisers and two destroyers, the Italian torpedo boats escaping as soon as it had become certain that the merchant ships were doomed. The loss of the cargoes led the German command to report that the fuel situation of the German warplanes in North Africa was critical.

The Italian and German forces in North Africa facing 'Crusader', the latest British offensive in the theatre, were facing an acute shortage of fuel and ammunition. At the urgent request of the Comando Supremo (supreme command of the Italian armed forces), the Supermarina (Italian navy general staff) prepared to send the 'M.41' major convoy of eight ships to sail on 13 December, and also an emergency lift to deliver the most urgently needed supplies using warships. Alberico da Barbiano and Alberto di Giussano, light cruisers of Ammiraglio di Divisione Antonino Toscano’s 4a Divisione Incrociatori, together with the torpedo boat Cigno, were selected for the operation as they were fast but too lightly protected for employment with the battle fleet, and therefore semi-expendable.

Alberico da Barbiano (Toscano’s flagship) and Alberto di GiussanoDa Barbiano (Toscano’s flagship) departed Taranto, on the 'instep' of the Italian 'foot' 08.15 on 5 December, reached Brindisi at 17.50 and there loaded about 50 tonnes of supplies, and then steamed to Palermo on the north coast of Sicily, which they reached on 8 December. Here the ships loaded another 22 tonnes of aviation fuel to alleviate the severe shortage of this spirit in Libya, which would prevent aircraft from escorting the planned supply convoys. Contained in unsealed barrels, the fuel was placed on deck above the the stern, even though this created a grave risk of fire if hit by British gunfire. The fuel was also at risk from the firing of the ships' own guns, preventing the use of the stern turrets unless the fuel was jettisoned. The two cruisers sailed unescorted from Palermo at 17.20 on 9 December, heading for Tripoli. At 22.56, when north of the island of Pantelleria, the light cruisers were spotted by a British aeroplane which had been undertaking a specific reconnaissance on the basis of 'Ultra' intercepts, and which then began to shadow them. At 23.55 Toscano, whose ships were now in the middle of the Sicilian Channel, decided to turn back to base, as the surprise required for the undertaking’s success had been lost, the volume of British radio traffic indicated the likelihood of an air attack, and worsening sea conditions was delaying his ships and further exposing them to British attack. Alberico da Barbiano and Alberto di Giussano regained Palermo at 08.20 on 10 December, after overcoming a British air attack off Marettimo. Toscano was strongly criticised by the Supermarina for deciding to abort the mission.

The 'M.41' convoy was planned for 13 December, but air cover by Libya-based aircraft would be impossible unless they received fuel from Italy. On 12 December it was decided that the same pair of the 4a Divisione Incrociatori's light cruisers, supplemented by a third such vessel in the form of Giovanni delle Bande Nere, would make a second attempt to reach Tripoli, the capital of Italian Libya. Giovanni delle Bande Nere was to carry more supplies, but could not sail as she succumbed to a mechanical breakdown, and her cargo was transferred to the other two cruisers. Alberico da Barbiano and Alberto di Giussano were therefore carrying 100 tonnes of aviation fuel, 250 tonnes of petrol, 600 tonnes of naphtha, 900 tonnes of food and 135 ratings on passage to Tripoli. The sterns of Alberico da Barbiano and, to a lesser extent Alberto di Giussano were packed with fuel barrels, massed so thickly that it was not possible to traverse the after turrets. Toscano held a briefing with his staff and officers from both ships, and it was decided that, in case of encounter with British ships, the barrels would be thrown overboard to enable the ships to open fire. Alberico da Barbiano and Alberto di Giussano, with their only escort, the torpedo boat Cigno (a second torpedo boat, Climene, was left in the port as a result of mechanical problems), sailed from Palermo at 18.10 on 12 December. The force had been instructed to pass to the north-west of the Aegadian islands group, then head for Cape Bon and finally follow the Tunisian coast to Tripoli at a speed of 22 to 23 kt in order to conserve to conserve fuel. Air cover, air reconnaissance and defensive ambushes MAS motor torpedo boats were planned to protect the convoy.

Commander G. H. Stokes’s British 4^th Destroyer Flotilla, comprising Sikh, Maori, Legion and Free Dutch Isaac Sweers, had departed Gibraltar on 11 December to join Admiral Sir Andrew Cunningham’s Mediterranean Fleet at Alexandria. By 8 December, the British had decoded Italian C38 radio signals about the Italian supply operation, information which included its course for Tripoli. The Royal Air Force sent a Vickers Wellington bomber on a reconnaissance sortie to sight the ships and create a deception to prevent any Axis perception of 'Ultra', and on 12 December the eastward-bound 4^th Destroyer Flotilla, heading toward the Italian ships, was ordered to increase speed to 30 kt and effect an interception. During the afternoon of 12 December, a Cant Z.1007bis aeroplane spotted the four destroyers off Algiers and heading east at an estimated speed of 20 kt. On receiving the report the Supermarina came to the conclusion that even if they increased speed to 28 kt, the destroyers would not reach Cape Bon until around 03.00 on 13 December, about one hour after the Italian ships. So Toscano, who had learned of the sighting while his ships were still in harbour, was not ordered to increase speed or alter course to avoid the British ships.

Following new 'Ultra' decodes, the British launched anther reconnaissance aeroplane, and this sighted Toscano’s ships at sunset on 12 December, after which the 4^th Destroyer Flotilla was directed to intercept the two cruisers, increasing speed to 30 kt. This speed, along with a one-hour delay that the Italian ships had incurred and which Toscano had not reported to the Supermarina, rendered useless the Supermarina’s previous calculations about the advantage that the two light cruisers would have. At 22.23 Toscano was informed that he would possibly meet 'enemy steamers coming from Malta', and at 23.15 he ordered his ships to go to action stations.

The 4^th Destroyer Flotilla sighted the Italian cruisers near Cap Bon, at 02.30 on 13 December, and at 02.45 on 13 December, at a point some 7 miles (11.25 km) off Cape Bon, the Italian ships heard the noise of a British aeroplane (in fact a radar-equipped Wellington), which located the Italian ships and informed Stokes about their position, and at 03.15 the four destroyers altered course to 157° to pass about 1 mile (1.6 km) off Cape Bon. Five minutes later, Toscano suddenly ordered full speed and an alteration to 337°, effectively reversing course. This sudden change disrupted the Italian formation, as neither Cigno, which was about 2 miles (3.2 km) ahead of the cruisers, nor Alberto di Giussano, which was following Alberigo da Barbiano received the order, and while Alberto di Giussano saw the flagship reverse course and imitated her but remained misaligned, Cigno did not notice the change until 03.25, at which time she too reversed course, but remained much behind the two cruisers.

Stokes’s destroyers were just off Cape Bon by this time and had spotted the Italian ships. Arriving from astern, under the cover of darkness and using radar, the British ships sailed close inshore and took the Italians, who were farther out to sea, by total surprise and launched torpedoes from short range. The course reversal accelerated the approach between the two groups and the Allied destroyers attacked together. Sikh and Legion fired their guns and launched four torpedoes against Alberico aa Barbiano at a range of less than 1,100 yards (1000 m), while Isaac Sweers opened fire on Alberto di Giussano and Maori launched six torpedoes against the same ship. Toscano ordered full speed and instructed his gunners to open fire, and ordered Alberto di Giussano to increase speed to 30 kt. Alberico da Barbiano, commanded by Capitano di Fregata Giorgio Rodocanacchi, also started a turn to port but then, at 03.22 and before she was able to open fire with her heavier guns, was struck by a torpedo below the foremost turret. Listing to port and slowing, Alberico da Barbiano was then raked with machine gun fire, which killed or wounded many men and set fire to the fuel barrels, and was soon hit by a second torpedo, which detonated in the engine room.

At 03.26 Maori fired two torpedoes at Alberico da Barbiano and opened fire with her guns, hitting the bridge. The cruiser was struck soon after this in the stern by another torpedo, possibly launched by Legion, and Alberto di Giussano was also hit by a torpedo and gunfire, and left disabled. The land behind the Allied destroyers made it impossible for the Italians to see them and Alberto di Giussano managed to fire only three salvoes. Within five minutes both cruisers were disabled. Alberico da Barbiano rapidly listed to port, while fires quickly spread all over the ship and into the sea by the floating fuel; the crew abandoned ship. At 03.35, Alberico da Barbiano capsized and sank in a sea of flame, taking Toscano, Rodocanacchi and another 532 men still on board. Alberto di Giussano was left engulfed in flame and dead in the water. Her crew fought to keep their ship afloat, but she also had to be abandoned, breaking in two and sinking at 04.20, with the loss of 283 men.

After a brief encounter with Isaac Sweers, Cigno rescued nearly 500 survivors; others reached the coast and another 145 men were later saved by MAS boats. The Italian losses totalled 817 men.

Toscano’s decision to reverse course has never been explained. He may have decided to turn back after realising that he had been spotted by an aeroplane, as he had done on 9 December, but a course toward the Aegadian islands group would have made better sense than the north-westerly course Toscano had ordered more than 30 minutes after the cruisers had been spotted. However, Toscano may have wanted to mislead the reconnaissance aeroplane about his real course, wait for it to leave and then turn back once more for Tripoli. He may have thought, from the aircraft noise, that torpedo bombers were approaching, and wished to reach waters farther away from the shore and from Italian minefields in order to gain freedom of manoeuvre. Toscano ordered his gunners to stand by; he may also have known that Allied destroyers were astern of his ships, and wanted to avoid presenting his stern to them because his after turrets were obstructed by the fuel barrels.

So far as the 'M.41' convoy was concerned, the Italians knew that a British submarine force (Unbeaten, Utmost and Upright) was almost certainly covering the Gulf of Taranto, and in fact during the morning of 13 December Upright sank two 6,837-ton freighters, Fabio Filzi and Carlo del Greco, from a feeder convoy despite the fact that they were being escorted by the destroyers Nicoloso da Recco and Antoniotto Usodimare. In the afternoon of 13 December, three freighters (5,324-ton Monginevro, 6,142-ton Napoli and 6,339-ton Vettor Pisani) escorted by the destroyers Emanuele Pessagno and Antoniotto Usodimare and the torpedo boat Pegaso, and the 4,768-ton German freighter Ankara escorted by the destroyers Saetta and Lanzerotto Malocello put to sea in two separate groups. A third group, comprising two freighters escorted by the destroyers Strale and Turbine, departed Argostoli for Benghazi.

Close cover for the convoy was provided by two powerful naval forces. The first, commanded by Ammiraglio di Squadra Carlo Bergamini, comprised the battleship Caio Duilio, heavy cruiser Gorizia, light cruisers Giuseppe Garibaldi and Raimondo Montecuccoli, and destroyers Maestrale, Alfredo Oriani and Vincenzo Gioberti, and the second, commanded by Ammiraglio di Divisione Conte Raffaele de Courten, comprised the battleship Andrea Doria, light cruisers Emanuele Filiberto Duca d’Aosta and Muzio Attendolo, and destroyers Aviere, Ascari and Camicia Nera. Following these were two groups of destroyers: the first comprised Corazziere, Geniere and Carabiniere, and the second Ugolino Vivaldi, Antonio da Noli, Lanzerotto Malocello, Nicoloso da Recco and Nicolo Zeno. More distant cover was provided, under the command of Ammiraglio di Armata Angelo Iachino, by the battleships Littorio and Vittorio Veneto, destroyers Granatiere, Fuciliere, Bersagliere and Alpino, and torpedo boats Centauro and Clio.

To cover the convoy operation, the Italians established, in areas to the east and south of Malta, a submarine screen comprising Santorre Santarosa, Narvalo, Squalo, Veniero and Topazio to guard against any intervention by the British warships of Agnew’s Malta-based Force 'K' (light cruisers Aurora, Neptune and Penelope supported by a number of destroyers), and in the area to the south of Crete Ascianghi, Galatea and Dagabur to guard against any intervention by Rear Admiral P. L. Vian’s Force 'B' (light cruiser Galatea and light anti-aircraft cruisers Euryalus and Naiad supported by a number of destroyers) of Cunningham’s Mediterranean Fleet.

Even as the 'M.41' convoy was getting under way, the British were beginning a supply run to Malta using the 9,776-ton commissioned fast transport Breconshire, covered by a cruiser and destroyer force, while the destroyers from the Cape Bon engagement, at Malta after the battle, were proceeding to Alexandria covered by the Malta strike groups, Force 'K' and Force 'B', in an operation starting on 15 December.

The passage of the 'M.41' convoy started badly for, soon after sailing on 13 December, one group was attacked by the British submarine Upright, which sank two of the ships; and later on the same day two of the freighters collided and had to turn back. The distant cover force was also sighted, in this instance by the submarine Urge, which torpedoed Vittorio Veneto, which was compelled to return to Italy.

The Italian naval high command was rattled by these events and also a report that a British force of two battleships was at sea, although the latter was in fact a decoy mission by the cruiser minelayer Abdiel, and ordered the ships associated with the 'M.41' convoy to return to Italy and await reinforcement. At this time the British were preparing their own operation, but their forces were depleted when the cruiser Galatea was torpedoed and sunk by U-557 just before 24.00 on 14 December. U-557 was accidentally sunk, less than 48 hours later, by the Italian torpedo boat Orione.

On 15 December Breconshire sailed from Alexandria with an escort forces comprising three cruisers and eight destroyers, under the command of Vian in Naiad. On the next day the four destroyers of Stokes’s 4^th Destroyer Flotilla departed Malta, covered by two light cruisers and two destroyers of Force 'K'.