HMNB Portsmouth the military and naval units destined for Sword Beach on the Normandy coast as a part of Operation Overlord and the D-Day landings on 6 June 1944. Troops destined for each of the landing beaches left from Portsmouth aboard vessels such as the armed merchant cruisers HMCS "Prince Henry" and HMCS "Prince David", escorted by the Canadian destroyers HMCS "Algonquin" and "Sioux". The majority of the naval support for the operation left from Portsmouth, including the Mulberry Harbours. Boathouse 4 (built around the start of hostilities) contributed to the construction of landing craft and support vessels as well as more
Oxfordshire and Buckinghamshire Light Infantry with the 1st Royal Ulster Rifles, to become part of the 6th Airlanding Brigade in 6th Airborne Division. The 2nd Ox and Bucks were due to take part in the invasion of Sicily (Operation "Husky"); however in April 1943 the battalion was advised that the 1st Airborne and not the 6th Airborne were to be deployed in the landings. As part of "Operation Deadstick" just before the landings on D-Day on 6 June 1944, D Company commanded by Major John Howard as well as 30 Royal Engineers and men of the Glider Pilot Regiment (a total of 181 men), were