Baron served in the Pioneer Corps of the British Army during World War II, and was among the first Allied troops to be landed in Sicily, Italy and on D-Day. Between 1943 and late 1944, he experienced fierce fighting in the Italian campaign, Normandy and in Northern France and Belgium. In 1945 he was transferred as an Instructor to a British Army training camp in Northern Ireland, where he received a serious head injury and was hospitalised for over six months. Other themes of his novels were London life, politics, class, relations between men and women, and the relationship between the individual and society.