Percy Montague Haydon was born in Islington, London, on 10 March 1895. His father William was a stationer who worked for the company who provided the Amalgamated Press with paper, and later an estate agent. His elder brother Rex became an editor with the AP, and Percy joined the company in 1900 as an office boy on The Sunday Companion, later working for Woman's Weekly and Sunday Circle.
He served in the West Yorkshire Regiment during the First World War. He was the only survivor of his regiment at the Somme, and was awarded the Military Cross. After the war he returned to the AP, editing Football Favourite and Sports Budget under the managing editor, his brother Rex.
In 1925 he was promoted, taking charge of a range of boys' papers - Boys' Friend, Boys' Realm, Boys' Herald, Pluck, Marvel, Union Jack, The Magnet, The Gem and Popular, as well as some of the 4d Library titles. He went on to launch Modern Boy (1928), Thriller (1929), Ranger (1931), Pilot (1935) and Wild West Weekly (1938).
He moved into comics, overseeing the launch of Knock-Out in 1939, but paper shortages during the Second World War led to the cancellation of all his other titles bar the Sexton Blake Library. After the war he was responsible for the launch of Jack and Jill, Playhour, Cowboy Picture Library, Valentine and others.
He became a director in 1955, and retired in 1961. He died in Worthing, Sussex, in the third quarter of 1971.
- Alan Clark, Dictionary of British Comic Artists, Writers and Editors, The British Library, 1998, p. 75