With most of the 6th Airborne Division, the battalion was involved in the British airborne landings in the early hours of 6 June 1944 (D-Day), code-named Operation Tonga, where the battalion had the task of destroying the Merville Gun Battery. After D-Day, they fought in the Battle of Normandy as normal infantrymen until the middle of August (see 6th Airborne Division advance to the River Seine). They later played a small part in the Battle of the Bulge in December 1944 and a large part in Operation Varsity in March 1945, the largest airborne operation of the war, involving over 16,000 paratroopers, where the 6th Airborne Division fought alongside the US 17th Airborne Division and both divisions suffered relatively heavy casualties in only a short amount of time. The 9th Battalion, Parachute Regiment ended the war in May 1945 near the Baltic sea and was later sent with the rest of the 6th Airborne Division in Palestine.