On D-Day his platoon landed approximately 500 yards from Ranville bridge. On arrival at the bridge, he left one section on the west bank and crossed the bridge with the other two sections. He met up with LieutenantDennis Fox on the far side of the bridge and found Fox's platoon in control of the bridge and surrounding area. By 00.26 hours on D-Day both bridges had been secured. The operation to capture the bridges was portrayed in the film The Longest Day (1962).
Sweeney was awarded the Military Cross (MC) for rescuing a wounded corporal of his platoon on 7 June 1944 while under heavy fire near Escoville. Sweeney was wounded during the Battle of Normandy in July 1944 and was evacuated to England. He rejoined the 2nd Oxfordshire and Buckinghamshire Light Infantry (the 52nd) in October 1944. He served in the Ardennes and the Netherlands from December 1944 to February 1945. He served in Operation Varsity: the air assault landing over the Rhine on 24 March 1945, and took part in the advance across Germany to the Baltic Sea. In October 1945 the 2nd Battalion, Oxfordshire and Buckinghamshire Light Infantry (the 52nd) was posted to Palestine, where Sweeney served during the Palestine Emergency.
Post Second World War
In 1946 Colonel Sweeney was appointed instructor at the Infantry Battle School near Haifa. He served as adjutant of the 1st Oxfordshire and Buckinghamshire Light Infantry in the Suez Canal Zone from 1951 to 1953. He commanded the Oxfordshire and Buckinghamshire Light Infantry guard of honour at the Coronation of Queen Elizabeth II on 2 June 1953. The senior warrant officer of the guard of honour was RSM, later Major John Stevenson MBE DCM.
He served in Cyprus as a company commander from 1956 to 1959 and was mentioned in dispatches. He was promoted to lieutenant colonel in 1962. Sweeney commanded the 1st Green Jackets (43rd and 52nd) at Penang from April 1962 to January 1964. The regiment was deployed to Brunei in December 1962 following an Indonesia backed uprising. He was mentioned in dispatches. He commanded the 1st Green Jackets (43rd and 52nd) in Borneo during the confrontation with Indonesia and was again mentioned in dispatches.
On 1 January 1966 the 1st Green Jackets (43rd and 52nd) became the 1st Battalion, Royal Green Jackets. He was defence advisor to the UK Mission to the United Nations in New York from 1966 to 1969. He then became head of public relations HQ BAOR, Germany. He was deputy commandant of the School of Infantry from 1971 to 1974.
Sweeney married Geraldine Follett in 1942, with whom he had two sons and three daughters. He died on 4 June 2001; a memorial service was held at Douai Abbey, Woolhampton, Berkshire.
Ambrose, Stephen. (1984). Pegasus Bridge - D-Day: The Daring British Airborne Raid. Simon & Schuster: London. ISBN0-7434-5068-X.
Howard, John and Bates, Penny. (2006). The Pegasus Diaries: The Private Papers of Major John Howard, DSO. Pen & Sword Books. ISBN978-1-84415-446-3.
Ryan, Cornelius. (1959). The Longest Day. Simon & Schuster: London.
Massy-Beresford, Michael (2007). Gliderborne: The story of the 2nd Battalion, The Oxfordshire and Buckinghamshire Light Infantry (the 52nd) in World War II.