The Mediterranean U-boat Campaign lasted from about 21 September 1941 to 19 September 1944 during the Second World War. Malta was an active British base strategically located near supply routes from Europe to North Africa. Axis supply convoys across the Mediterranean Sea suffered severe losses, which in turn threatened the fighting ability of the Axis armies in North Africa. The Allies were able to keep their North African armies supplied. The Kriegsmarine tried to isolate Malta but later it concentrated its U-boat operations on disrupting Allied landing operations in southern Europe.Some 60 German U-boats made the hazardous passage into the Mediterranean Sea from 1941. Only one completed the journey both ways. Karl Dönitz, the Commander-in-Chief, U-boats, Befehlshaber der Unterseeboote (BdU) was always reluctant to send his boats into the Mittelmeer but he recognised that natural bottlenecks such as the Straits of Gibraltar were more likely to result in shipping being found and attacked than relying on finding it in the vast Atlantic Ocean. The U-boats were sent to assist the Italians, although many were attacked in the Strait of Gibraltar and nine were sunk while attempting the passage and ten more were damaged. The Mediterranean is a clear and calm body of water which made escape more difficult for the U-boats. The Axis failed in their objective. Source: Wikipedia (en)