This illustrated study explores the detail of the Royal Navy’s huge operation on D-Day and in the weeks after, as the fleet went into action to support history’s biggest amphibious landings. Although D-Day is perhaps the most written-about event in military history, little has been published on the detail of the sea power that Overlord relied upon. In this book, critically acclaimed historian Nick Hewitt examines the fleet that secured the British Assault Area from the eve of D-Day until the end of the assault phase of operations on 30 June 1944. While led and dominated by the Royal Navy, it was multinational, including forces from Canada, Norway, and the Free French. The invasion had many moving parts and proved there is more to a successful assault than simply putting soldiers ashore on a beach. This book explains the minesweeping that allowed the landings to take place, and the various naval operations that brought British and Canadian troops to the beaches. It also explores how the fleet defended the British Assault Area from counterattacks by enemy destroyers, coastal forces, mining, and special attack units, and how it sustained the build-up that fed resources to the growing Allied forces. Illustrated with archive photos, original artwork and 3D diagrams and maps, and drawing upon primary documentation that has previously gone largely unused, this book offers a fresh exploration of the sea power behind D-Day.