The D-Day landings of June 1944 were one of the most ambitious undertakings of all time, and their success one of the greatest military accomplishments. Operation Neptune was the initial assault stage of the broader Operation Overlord, the liberation of northwest Europe. It was a hugely complex undertaking involving several thousand ships and aircraft and hundreds of thousands of men, as the Allies took on Germany’s vaunted Atlantic Wall. In the words of the man most responsible for the plan, Admiral Bertram Ramsay (Allied Naval Commander-in-Chief), ‘It is to be our privilege to take part in the greatest amphibious operation in history… Our task, in conjunction with the Merchant Navies of the United Nations, and supported by the Allied Air Forces, is to carry the Allied Expeditionary Force to the Continent, to establish it there in a secure bridgehead and to build it up and maintain it at a rate which will outmatch that of the enemy.’ The landings in Normandy represented the culmination of several long campaigns to put in place the strategic preconditions for the return to the continent, as well as marking the beginning of the campaign to finish the war in Europe. This volume provides the complete text of the Battle Summary written shortly after the war by the Admiralty historical staff, covering the planning, preparation and execution of the operation as well as the subsequent consolidation, together with the maps and detailed appendices from the original work. This is accompanied by a comprehensive introduction, newly written for this volume, that explains the context for the operation as well as an overview of further reading on the subject. This is the first volume in Helion’s new series, 'Naval Staff Histories of the Second World War’. The series aims to make available to a broad authorship these indispensable studies of the key operations of the war.