He became a teacher at St Philip's prep school in Kensington, and was due to join the London Oratory when the Second World War broke out.
He was commissioned and joined the Intelligence Corps before being transferred to the 2nd Battalion, Essex Regiment, part of the 56th Independent Infantry Brigade.
Very early one morning at the time of the Battle of Falaise, he was responsible for a reconnaissance far into German lines in a jeep with only a driver for support.
[7] Father Hugh succeeded to the baronetcy on the death of a distant cousin, Sir Richard Barrett-Lennard, 5th Baronet, at Swallowfield Park, Reading on 28 December 1977.
He also addressed the congregation and unveiled a plaque near the cathedral entrance to the soldiers of the 56th Infantry Brigade–the 2nd Battalions of the Essex Regiment, the Gloucestershire Regiment and the South Wales Borderers–who landed on Gold Beach on 6 June 1944 and pushed inland to secure the right flank of the British Second Army by that evening, liberating Bayeux the following day.
[8] He apparently inherited this from his eccentric great grandfather, Sir Thomas Barrett-Lennard, 1st Baronet, who wore very old and shabby clothing and had been mistakenly apprehended by the police as a miscreant and also assumed to be a servant when he opened the park gates to a carriage for which he received a tip.