At no point during World War Two were the fluctuating fortunes of both the Allies and the Axis in the Battle of the Atlantic so fully on display as the first two weeks of March 1941.

-26 February: Battlecruisers Scharnhorst and Gneisenau broke out into the Atlantic. They sink 22 ships around the Azores and Cape Verde Islands and returned on 14 Mar.

-1 March German pocket battleship Admiral Sheer broke out into South Atlantic, sinks six ships, returned on 27 March.

-2 March: U Boat wolfpack savaged fast Convoy HX-109. Convoy was found due to German expertise in radio signal direction finding which each U-boat was equipped. In all, 83 ships were sunk by U boats over these three weeks, an above average total.

-4 March: Operation Claymore. The first large scale commando raid of the war. Commandos raided the fish oil and glycerin factories of the Norwegian Loften Islands. Wildly successful, but even more so because the commandos captured four rotors of a German enigma machine which would allow the British to decode German naval signals traffic.

-6 March: In a reaction to estimates from the Home Office that Great Britain had just five months of essential supplies left, even with severe rationing, Winston Churchill issued guidance that the Battle of the Atlantic was the top priority of the British and Commonwealth armed forces.

-7 March: Germany’s #3 U boat captain and hero of the raid on Scapa Flow, Gunther Prien, was killed when his U boat was sunk in an attack on convoy OB-293.

-7 March: 12 German E- boats (PT boats) nearly destroyed convoys FN-426 and FS-429 off the English coast.

-11 March: the German cruiser Admiral Hipper sank 14 of 19 freighters in convoy HG-43 off the African coast near Sierra Leone.

-11 March: Lend-Lease.

-12 March: RAF bombers severely damaged the FW-220 factories near Bremen, and due to bureaucratic infighting they never recovered. The FW-220 “Condor” was Germany’s only four engine bomber. Allied convoys feared the big long range converted passenger plane because a sighting of one inevitably meant one or two sunk ships from bombs, and a wolfpack attack within 24 hours.

14 March: German auxiliary cruiser Atlantis sank or captured four ships in the south Atlantic. In all, the Atlantis and her sister ships, the most famous of whom were the Komoran and Pinguin, sank or captured 14 ships in these two weeks.

16 March: the German’s #1 and #2 U boat captains, Otto Ketchmer and Jochim Scepke were both killed separate wolfpack attacks in the North Atlantic. Scepke’s U-100 was the first U-boat lost while tracked by radar.

-16 March: German battleship Bismarck and cruiser Prinz Eugen began sea trials in the Baltic.