Born John (not Jon) Devon Roland Pertwee, he made his screen debut as early as 1937 in two films co-written by his father. A Yank at Oxford, the first major Anglo-American feature, was a huge pre-war success starring Robert Taylor, Vivien Leigh and Lionel Barrymore, and Dinner at the Ritz featured David Niven. His father's stage play To Kill a Cat also provided Pertwee with his West End debut, at the Aldwych Theatre in 1939.
Wartime service in the Navy led to Pertwee's radio success, but he continued in films for most of his career, with appearances in mostly comedy features such as Carry On Cleo (1964), Carry On Cowboy (1965), Carry On Screaming (1966), A Funny Thing Happened on the Way to the Forum (1966) and One of Our Dinosaurs is Missing (1975). He even stood in for Danny Kaye in the London scenes of Knock on Wood (1954) and gave his voice to the children's films Wombling Free (1977) and The Water Babies (1978). His last films, the Cannon and Ball picture The Boys in Blue (1983) and the dreadful Carry On Columbus (1992), were more a testament to the sorry state of British comedy films than to his ever-reliable talents.
The big screen never provided Pertwee with a star vehicle. Instead, it was as the third Doctor Who on television and the walking, talking scarecrow Worzel Gummidge that he became best known to the nation. It was his enthusiasm for Worzel, and his recollection of reading the books by Barbara Euphan Todd in the Thirties, that led him to take the idea to Southern Television, which produced four series of Worzel Gummidge (1979-81), as well as a Christmas special, A Cup o' Tea an' a Slice o' Cake (1980).
Unfortunately, Southern Television lost its ITV franchise and no more programmes were made until the series was resurrected by a producer in New Zealand. Two series of Worzel Gummidge Down Under (1987, 1989) were made, screened in Britain on Channel Four, and at the time Pertwee told me: "It's my baby. I felt tremendous responsibility for it. I'm the one who has nurtured it and kept it going."
Pertwee made his television debut back in 1946, playing the Judge in a BBC production of Toad of Toad Hall, a screen adaptation of A.A. Milne's play from Kenneth Grahame's The Wind in the Willows. Kenneth More played Mr Badger.
Pertwee's later television appearances included Round the Bend (1956), the adventure series Ivanhoe (1958), the tramp-steamer sitcom Glencannon (1960) and The Avengers (1967), before he took over as the Timelord in Doctor Who (1970-74). By now a television star in his own right, Pertwee was hired by Thames Television to present three series of the ITV crime quiz Whodunnit? (1973-78), landed a guest role in The Goodies (1975) and starred as a psychiatrist consulted by Father Christmas in The Curious Case of Santa Claus (1982).
In 1992, he appeared with his actor son Sean in the television film Virtual Murder. He was last seen on screen in March as a guest presenter in the Channel 4 magazine programme Food File, reporting on how insects feed on humans' breakfast cereals, even eating through the cardboard boxes. Pertwee's daughter, Dariel, also continues the family acting tradition, and his cousin Bill is still remembered for his role as ARP Warden Hodges in Dad's Army.