The Mediterranean U-Boat Campaign, 1940-1943

During the first two years of World War II, the Germans were largely uninterested in the Mediterranean Sea; to the Italians and their common enemy, the British, it was of paramount importance. Italian setbacks over the course of 1941 prompted the Germans to commit resources to an escalating involvement in the region; while the effort resulted in some spectacular successes in the short term, it also represented the diversion of men and other military assets from their primary objectives. This applied to the U-Boat arm of the German Navy as well; between 1941 and 1943, a small number of U-Boats were deployed to the Mediterranean Sea in an effort to secure Axis control of North Africa.

The naval struggle for control of the Mediterranean began when Italy declared war on Great Britain. Italy’s interest in the Mediterranean was self-evident; a peninsula, Italy was almost entirely surrounded by this body of water, while its colonial possessions were just on the other side of it, in North Africa. Italy’s security depended on control of the Mediterranean, or at least, the central part of it.

For Britain, control of the Mediterranean was no less essential, if less immediately apparent. By using the Suez Canal to enter or exit the Mediterranean, vessels could travel between the Indian Ocean and the Mid-Atlantic over only 2,000 miles; without the Canal and the freedom to pass through the Mediterranean, the same two points were connected by 13,000 miles of travel around Africa. The success of the British war effort depended on the maintenance of the Mediterranean route, but that meant traveling through waters watched by the Italians. The Mediterranean became a natural theater of war.

In theory, Italy seemed to have the upper hand in this fight. Italy had more vessels in the region, and most of them were newer than the British vessels. This applied to submarines as much as to surface vessels, and with 113 submarines, the Italian Navy (Regia Maritima) was second only to the Soviet Fleet in its submarine strength. The British, however, made much better use of its air assets than the Italians; with aircraft carriers to bolster their fleets and land-based aircraft on Malta, the British enjoyed startling successes both in fleet actions and in the protection of its own shipping, or in attacks on Italian shipping. This disparity in air power also affected Italy’s submarine efforts. The waters of the Mediterranean are generally clear, and consequently, submarines could be seen from the air even when submerged to 110 feet below the surface. The Mediterranean is shallow in many places, and so this constituted a substantial disadvantage.

Grand Admiral Raeder was quite taken with the strategic possibilities of a major German intervention in the Mediterranean on behalf of the Italians. A substantial German commitment of resources, including U-Boats, offered more than the prospect of neutralizing Malta and easing the pressure on shipping between Italy and Libya; gaining control of the Mediterranean would deliver a crippling blow to the British war effort, especially with regard to the delivery of oil from the Middle East.

In this, Raeder thought like a traditional naval strategist, looking for the best way to use the material resources that he had at his disposal to deal the strongest strategic blow to his adversary that he could muster. Admiral Dönitz, Commander in Chief of the submarine arm, saw instead with the eye of the specialist. He had already committed his U-Boats to a strategy of cutting Britain off from all outside supply sources; success in the Battle of the Atlantic would have accomplished all that success in the Mediterranean might have brought, and far more. He considered the effort a needless distraction, and Hitler, interested in neither naval matters nor the Mediterranean Sea, was inclined to agree with him.

British successes in the summer of 1941 changed Hitler’s mind. Having already sent Rommel to North Africa early in the year, and then having intervened in Yugoslavia, Greece and Crete to rescue Mussolini’s faltering efforts in the Balkans, Hitler was prepared to offer additional aid, building on the aforementioned successes. In September, U-371, a Type VIIC U-Boat, became the first vessel of the new 23rd U-Boat Flotilla to reach Mediterranean waters, bound for its new base at Salamis in Greece. On September 11, the Flotilla was officially constituted with nine Type VII boats, three of which were Type VIIB vessels, with the remainder consisting of Type VIIC boats.

The U-Boats were subject to the same circumstantial challenges that had faced Italian submarines, however, and overall, the 23rd Flotilla accomplished little. U-331 scored one telling blow on November 25, however: it sank a British battleship, the HMS Barham, near Sidi Barani. The prospects were better in the western and central Mediterranean, where Italian-based aircraft and naval vessels could offer support. Just twelve days before the U-331 sank the Barham, another U-Boat, the U-81, struck the carrier Ark Royal. The U-81 had just entered the Mediterranean on the 12th; on the 13th, it encountered the British task force (Force H) near Gibraltar and crippled the Ark Royal with a single torpedo; the carrier sank the next day. The focus of German attention would soon shift to the west.

December brought a major Luftwaffe presence to Sicily in the form of Fliegerkorps 10; the objective was to eliminate the threat posed by Malta to the Axis supply lines to Libya. Eighteen U-Boats were also sent to the area. The new arrivals were organized into the 29th U-Boat Flotilla, and their base of operations was La Spezia in Italy. The cumulative effect of U-Boats, air power and surface vessels made the 29th Flotilla more successful, and in May, the 23rd Flotilla was merged into the 29th. The base at Salamis remained in use, however; in addition to Salamis and La Spezia, Toulon in France and Pola in Croatia served as major submarine bases.

The U-Boats were only a part of the submarine force available to the Axis in the Mediterranean, and a small part at that. Throughout the campaign, at least 62 (and no more than 68) U-Boats operated in the Mediterranean, but at any given time, the number of operational U-Boats never exceeded 25. Italian submarines outnumbered them substantially. A good example of this disparity concerns Operation Pedestal, when the British made a desperate push to resupply Malta at the height of the unconventional siege. Eleven Axis submarines were involved in the effort to keep the siege in effect, ten of which were Italian and only one, U-73, was German. U-73 struck the greatest blow, however; it scored four hits on the British aircraft carrier Eagle, which sank almost immediately.

The loss of capital ships draws the most attention in the history books, but the typical target of submarines in World War II was far humbler: merchant vessels, transport ships and the like. This was true of both sides, especially in the middle of the Mediterranean, where British and Axis supply lines crossed near Malta. In all, the U-Boats accounted for nearly 450,000 tons of shipping, having sunk 95 vessels.

1943 marked the effective end of the Battle of the Mediterranean, and U-Boat operations in the Mediterranean largely ended that year as well. It was in that year that combined Anglo-American strength succeeded in expelling the Axis from North Africa. Without any supply lines to Africa to defend, the Axis attention in the region shifted from the command of the seas to the repulse of Allied invasion plans in Italy. The 29th Flotilla moved its base from La Spezia to Toulon, but at most it delayed the end of the U-Boat presence in the Mediterranean by a small margin. Allied naval dominance ensured the destruction of every U-Boat in that sea by the end of summer; Aug. 19, 1944, marked the scuttling of U-466, and so the last U-Boat in the Mediterranean was gone.

Like the Battle of the Atlantic, the U-Boat campaign in the Battle of the Mediterranean can be seen as an impressive failure. In the end, it failed to achieve its objectives, although it had achieved signal successes and came close to accomplishing its ends along the way. A careful consideration of the circumstances in the Mediterranean suggests that there was nothing more that the U-Boat arm could have accomplished by itself. This battle was truly a battle of combined arms, in which surface and submarine naval assets operated closely with air force elements on both sides. Malta was the point of intersection of all of these elements, and it is there that a decisive blow could have been struck, but not by submarines. The only way to change the outcome of the battle would have been to force the capture of Malta by Axis forces. This would have been possible, especially in the spring of 1942, when the siege had become the most desperate. The seizure of Malta would have required ground troops, however, and among them, paratroopers would have been necessary. Hitler had set his mind against the large-scale use of paratroopers after the Crete campaign, however, and any speculation in this direction requires Hitler to be more realistic than he was. As it was, the German commitment to the Mediterranean was always a half-hearted one. The level of U-Boat deployment reflects this reality, and in that context, the U-Boats accomplished much, but failed to win the war for the Axis.



Dear, I.C.B.  The Oxford Guide to World War II. Oxford, 1995

Porter, David.  World War II Data Book: The Kriegsmarine 1935-1945.  Amber, 2010

Ross, David.  The Essential Naval Identification Guide: Submarines 1914-Present.  Amber, 2012

Stilwell, Alexander, ed.  The Second World War: A World in Flames.  Osprey, 2004


© 2013.  All rights reserved.