The 2/4th Battalion was raised in 1939 as a 2nd Line Territorial Army battalion duplicate of the 1st Line 4th Battalion, later redesignated the 1/4th Battalion. Both the 1/4th and 2/4th battalions served in the 164th Infantry Brigade, part of the 55th (West Lancashire) Infantry Division. In 1943, the 2/4th Battalion was transferred to the British Army's airborne forces and converted to become the 13th Parachute Battalion of the Parachute Regiment, part of the 5th Parachute Brigade, which itself was part of the newly raised 6th Airborne Division. The 13th Parachute Battalion saw combat during Operation Tonga, the British airborne landings in the early hours of 6 June 1944, D-Day. The battalion served as normal infantrymen for the duration of the Battle of Normandy until being withdrawn, with the rest of the division, to England in September 1944. The 6th Airborne Division was then sent to Belgium in December 1944 to fight in the Ardennes offensive, the Battle of the Bulge. They were then involved in the largest airborne drop of the entire war with over 16,000 airborne troops taking part, known as Operation Varsity, with the US 17th Airborne Division.