Escorts Carriers Winston Churchill once stated that the only thing that truly frightened him during the war was the prospect of losing the Battle of the Atlantic. In March 1943, it seemed like the Allies were going to lose that battle. A total of 477,000 tons of Allied shipping was lost at the cost of only 12 U-boats. But by July 1943 the battle had shifted dramatically in favour of the Allies. During that month, only 123,000 tons of shipping was lost, in exchange for the loss of 53 U-boats. The reasons for this turnaround were partly due to the air cover provided by Escort Carriers throughout the voyage. In 1941 it became apparent that frontline aircraft carriers would be essential for combat operations. Consequently, a fleet of low-cost auxiliary aircraft carriers would be required to provide aircover for the convoys. This talk covers the development of these warships from converted merchant ships to bespoke vessels and their role in the defeat of the U Boats and thus securing the Atlantic supply lanes enabling D Day to take place.