During 1940 Churchill and the War Cabinet regarded safe passage for British ships in the Mediterranean Sea to be of paramount importance. Despite the catastrophic evacuation of the British Expeditionary Force from Dunkirk and the threat of imminent invasion from across the English Channel, it was considered that the vital trade routes to North Africa and the Middle East must be kept open.

The German Kreigsmarine were at that time committed to North Sea and Atlantic naval forays. The French surrender left their fleet in disarray, some wishing to fight against their invaders and others supporting the Vichy government. The Royal Navy finally put matters to rest with the destruction of the French fleet in Toulon, an unsavory but entirely necessary act of war. However, there remained the powerful and modern Italian fleet which, if allowed to run amok within the Mediterranean, could cause mayhem for the Allies. Their fleet had to be destroyed at all costs. This is the story of how this was achieved during 1940.