Born as an illegitmate baby in London on 19th June 1915 as Leslie Wiilet Brannen.
He never knew his wealthy father who lived in Mayfair. When he was six months old, his mother took him to Tyneside where she married a miner, Bill Dennison and he found himself with this name for much of his life.
Humiliated as the "bastard" son, Les felt himself the whipping boy and drudge to his stepbrothers and stepsisters, his anger driving a wedge between them. He was sent down the mines, aged 13, terrified of the dark. They lived in grinding poverty and, aged 19, he went in search of work in the Midlands, soon moving the whole family to Coventry. There he joined Keresley pit and the Communist Party. He met Vera Painter and they were married in 1938.
At the outbreak of war he joined the Army Service Corps as a fitter. He was captured by the Japanese at the fall of Singapore in 1942. A 19-day forced march through the jungle took him and his fellow POWs to the Burma railway, where they were employed as slave labour. The work included building the last stretch of one of the bridges over the River Kwai between Burma and Thailand. Cholera and dysentery were rife and none of his friends survived. He worked there for three years and seven months in appalling conditions, and witnessed the decapitation of 14 of his fellow prisoners. Seizing a chance for revenge, he killed a Japanese guard at the edge of the river, throwing him into the rocks and water below. Forced to carry his dying comrades, Dennison was one of only 400 survivors out of a group of 1,600 POWs. On liberation he weighed just 5st 4lb.
On his return to Coventry he donated part of his war gratuity to the local Communist Party, trained as a plumber and was an agitator at the Standard Motors car plant before joined the building industry. He became convenor of shop stewards on a site, representing some 400 workers. In 1959 a plasterer and fellow shop steward (Dennison represented plumbers) confronted him about his family life, for Dennison was so filled with hate after his Japanese experience that he has become a perpetrator of domestic violence.
Overnight, Dennison was filled with a search to "find God" and left the Communist Party. He later converted to the Roman Catholic faith. Dennison had thrown his eldest son Karl, named after Karl Marx, out of the home for wanting to marry a major’s daughter, which Les had seen as a class betrayal. Now he apologised to his son and they were reconciled. At work, he began insisting from his fellow workers on "a moral day’s work rather than a legal day’s work". In 1962, Dennison encountered a Japanese group at the Moral Re- Armament centre for reconciliation in Caux, Switzerland. As a member of the British veterans’ Burma Campaign Fellowship Group, Dennison now became a high profile spokesman for a reconciliation with the former Japanese enemy. He died in Coventry on 10th April 2006.