Arthur Leslie Morton was born in Suffolk in 1903. After studying at Cambridge University he taught at Summerhill, the progressive school run by A. S. Neil.

A.L. Morton joined the Communist Party and published his Marxist work People's History of England in 1938. Other books by Morton include Socialism in Britain (1963), The English Utopia (1969), World of the Ranters: Religious Radicalism in the English Revolution (1970), The British Labour Movement, 1770-1920 (1973), Freedom in Arms: Levellers' Writings (1976), The Life and Ideas of Robert Owen (1978) and a study of William Blake, entitled, The Everlasting Gospel (1982).

Leslie Morton died in 1987.