Born in Sheffield, he showed an early artistic aptitude such that he won a scholarship to a London art school at eleven years old. Sadly, his mother’s MS made it impossible to take up the place but he later entered the College of Arts & Crafts in Sheffield where he studied under James Anthony Betts, staying on to teach there himself for a year after his graduation. That year he also held his first solo show in a commercial gallery before beginning a scholarship post graduate course at the Royal College of Art in 1933.

On graduating from the RCA painting department in 1936 he was quickly taken up by two of leading commercial patrons of the arts, Frank Pick at London Transport and Jack Beddington at Shell. This supplemented wages from teaching anatomy and lithography at the Camberwell College of Art and the South London Working Man’s College. In 1938 he married Eileen Kohn, a fellow student at the RCA and sister of the artist Edwin Ladell, moving to Harcourt Terrace in Chelsea.

At the outbreak of war Mozley joined the Royal Engineers and like many fellow artists was transferred to the Camouflage Unit in Leamington Spa. His first commanding officers were Frederick Beddington (brother of Jack and post-war director of Wildenstein Gallery) and the fashion designer Victor Steibel. He would travel with colleague Edward Seago on painting visits and with whom he remained friends for many years. He approached the War Artists Advisory Committee but his lack of major exhibitions before the war ruled out his appointment as an official war artist. However, they recognised his abilities and transferred him to Military Intelligence where he rose to the rank of Lieutenant Colonel. He adapted well to the highly secretive world and used his skills of observation and the effects of light and colour in concealing the build-up of troops and equipment during the preparations of Operation Overlord.

His war-time connection served him well in the subsequent peace. Victor Steibel and his partner, the composer Richard Addinsell, made many introductions in the theatre and film world that led to numerous commissions. He designed a number of theatre and film posters, stage sets, costumes and programmes for Sir Alexander Korda between 1946 and 1955. In the literary realm he produced more than three hundred book jackets and over a hundred illustrations for books, magazines and newspapers. His work appeared in the associated ephemera for all the principal national events of the era - The Royal Wedding, the Festival of Britain, Schools Prints, Lyon’s Lithographs and the Coronation paintings.

Throughout he continued to paint and exhibit, contributing regularly to commercial galleries and the Royal Academy Summer Exhibition. His commercial posters were commissioned by the great corporate giants of the day.

His work is held in the permanent collections of the Victoria & Albert Museum, The Tate Gallery, The Imperial War Museum and The British Museum.