Math doesn’t lie. The British Isles required X tonnage of shipping resources to maintain the war effort and the Germans were sinking more tonnage than was being built. Churchill knew it, and if nothing changed the war would be over by the end of the year. For Grand Admiral Erich Raeder, Chief of the Kriegsmarine (the German Navy) that was not soon enough. Raeder was a surface man, and he was being outshone by his erstwhile subordinate, Adm Karl Doenitz, the chief of the U-boats. Ton for ton, Raeder’s surface raiders (hehe) were much more effective than the U-boats but there were only so many. Raeder wanted a decisive blow to knock out Great Britain. Fortunately for him, the brand new battleship Bismarck just finished its sea trials in the Baltic. The Bismarck was the most powerful battleship in the seas around Europe, and clearly outclassed anything the British had. In early May 1941, Raeder conceived of Operation Rheinübung (Exercise Rhine) to bring Great Britain to its knees once and for all.
Britain took extraordinary precautions to prevent German capital ships from breaking out into the Atlantic not because they sank many ships (though in some cases they did), but because they sent the convoy system into chaos. This chaos added weeks to transit times in some cases, and scattered some convoys which made the stragglers easy pickings for aux cruisers and U-boats. In March, the cruiser Admiral Hipper nearly shut down the sea lanes along the west coast of Africa, and the Admiralty was still recovering from the damage done by the breakout of the battlecriusers Scharnhorst and Gneisenau in April.
Operation Rheinübung was the plan to re-break out the battlecriusers from France, and breakout the pocket battleship Admiral Scheer from Norway along with the Bismarck and heavy cruiser Prinz Eugen from the Baltic, so they could form an unstoppable flotilla in the Atlantic. The British would be forced to mass their fleet of older battleships and battlecruisers to take them on. While the Brits consolidated, the convoys would be at the mercy of the Germans.
In the second week of May 1941, the Bismarck and Prinz Eugen took on extra supplies, prize crews for future captured vessels, and the operation’s commander, Vice Admiral Gunter Lutjens. On the night of the 18th, Lutjens quietly slid out of the harbor at Gdynia, Poland.
It was the beginning of Churchill’s worst nightmare.