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
No. 6 Commando No. 6 Commando took part in was Operation Torch, the Allied landings in Algeria in November 1942. Later, it joined the advance into Tunisia in 1943. On 6 June 1944, it participated in the D-Day landings in France as part of Operation Overlord, coming ashore with the 1st Special Service Brigade which was tasked with linking up with the troops from the 6th Airborne Division on the eastern flank of Sword. Following this, No. 6 Commando were used in the defence of the beachhead and the subsequent operations to break out from Normandy before being withdrawn with the rest of