Operation Neptune
Ramsay was reinstated to the Active List on 26 April 1944 and promoted to the rank of admiral on 27 April 1944. He was appointed Naval Commander-in-Chief of the Allied Naval Expeditionary Force for the invasion.
In this, he executed what has been described by historian Correlli Barnett as a "never surpassed masterpiece of planning" — coordinating and commanding a fleet of almost 7,000 vessels to delivering over 160,000 men onto the beaches of Normandy on D-Day alone, with over 875,000 disembarked by the end of June.
He defused a potential conflict between Prime Minister Winston Churchill and the British Sovereign, King George VI, when Churchill informed the King that he intended to observe the D-Day landings from aboard HMS Belfast, a cruiser assigned to bombardment duties for the operation. The King, himself a seasoned sailor and a veteran of the Battle of Jutland in the First World War, likewise announced that he would accompany his Prime Minister. The two were at civil loggerheads until meeting with Admiral Ramsay, who flatly refused to take responsibility for the safety of either of them. Ramsay cited the danger to both the King and the Prime Minister, the risks of the planned operational duties of HMS Belfast, and the fact that both the King and Churchill would be needed at home in case the landings went badly and immediate decisions were required. This settled the matter and both Churchill and King George VI remained ashore on D-Day.
While the port of Antwerp was vital for the Allies after D-Day, Admirals Cunningham and Ramsay warned SHAEF and Montgomery that the port was of no use while the Germans held the approaches; saying it would be of much use as Timbuktu! But Montgomery postponed the Battle of the Scheldt, and the delay in opening the port was a grave blow to the Allied build-up before winter approached.