Returned to Great Britain from the U.S.
Joined the advertising firm, the J. Walter Thompson Co.
Worked as a writer, illustrator and art director of advertising shorts
Worked at George Pal studios in Holland
Worked in the script department at Pinewood Studios; provided (along with Sinclair Hill) the original story for the feature, "Midnight Menace"
Worked on the story and/or screenplay of the following shorts (generally for the filmmaking team of John Halas and Joy Batchelor): "Train Trouble" (1940), "Carnival in the Clothes Cupboard" (1940), "Fable of the Fabrics" (1942), "Subject for Discussion" (1943, dir. Hans M. Nieter), "Abu's Dungeon", "Abu's Harvest", "Abu's Poisoned Well" and "Abu Builds a Dam" (all 1943)
Served the British Ministry of Information (MoI) as an animator of short propaganda films during WWII
Wrote and co-directed (with Roger MacDougall) several documentary shorts for the MoI as part of the "Pathe Gazette" series: "Kitchen Waste for Pigs" (1942), "Contraries/The Walrus and the Carpenter" (1943) and "Nero/Fiddling Fuel/Save Fuel" (1943)
Became head of the newsreel and documentary unit of the Psychological Warfare Branch of the MoI
Co-wrote the screenplay for "Saraband for Dead Lovers"
Signed contract as screenwriter with Ealing Studios
Feature directorial debut, "Whisky Galore" (U.S. Release title, "Tight Little Island")
Provided additional dialogue for, and was uncredited second unit director on "The Blue Lamp"
First feature writing credit on a film he also directed: co-authoring the screenplay for "The Man in the White Suit"
First U.S. Film, "Sweet Smell of Success"
Credited with "script assistance" on "Fanfare", directed by Bert Haanstra
Began work directing "The Devil's Disciple"; was fired after a week and was replaced by Guy Hamilton
Directed Broadway production, "Face of a Hero"
Began directing "The Guns of Navarone"; injured his back after several weeks of work; replaced by J. Lee Thompson
Directed last British film, "Sammy Going South"
Directed an episode of the TV drama series, "The Defenders"; episode title, "The Hidden Fury"
Directed additional scenes (uncredited) of the U.S. Film, "Oh Dad, Poor Dad, Mama's Hung You in the Closet and I'm Feelin' So Sad"
Last film, "Don't Make Waves"
Named dean of the film and video department of the California Institute of the Arts; received funding by the Walt Disney Foundation
Was an advisor for the short, U.S.-made film, "Practical Film Making"
Was the subject of a documentary film made for TV, "Mackendrick"
Named a fellow of the California Institute of the Arts; resigned deanship, but continued teaching