In 1948, Johns bought a one-way ticket to Britain and learned his craft working in repertory theatre at
Southend-on-Sea for almost five years. He began to appear in British films from the mid-1950s, including a bit part in the classic
Ealing comedy The Ladykillers (1955). He ran a small hotel in London during the 1950s, and was a member of the
English Stage Company at the
Royal Court Theatre during the
Angry Young Men period when new playwrights, including
John Osborne, introduced new themes to British theatre. His most famous character, Barlow, was noted for his hard edges, owing much to the changes in characterisation pioneered at the Royal Court. In 1961, he appeared in
The Avengers Season One episode "The Frighteners" in the role of Sir Thomas Weller. In 1968 he was in the
spy-fi series
Department S in the first filmed episode "The Man in the Elegant Room." In 1962, he was cast in the role of Barlow in
Z-Cars . During the run (1962–1978) of
Z-Cars, he transferred his character to the spin-off series,
Softly, Softly (1966–1969), and later
Softly, Softly: Task Force (1969–1972). He also played the voice of the mysterious "Guvnor" in ''
The Great St Trinian's Train Robbery'' (1966). He was the subject of
This Is Your Life in October 1963 when he was surprised by
Eamonn Andrews at BBC Television Centre. In the 1970s, he starred in a third spin-off series,
Barlow at Large (1971, 1973), which saw the character transferred to
British Intelligence: it was later retitled simply
Barlow (1974–1975). Although the Barlow character remained popular (and appeared in another spin-off, in which he investigated the
Jack the Ripper murders), ratings for these solo spin-offs declined, and the final series ended in 1975. Barlow was seen once more in 1976, in the series
Second Verdict. Johns appeared as President of the Council
Bradshaw in the 1970 award-winning film
Cromwell with
Richard Harris in the role of
Cromwell and Sir
Alec Guinness as
King Charles I. In 1973, Johns was named BBC TV Personality of the Year by the
Variety Club of Great Britain. He portrayed the
apartheid-supporting Namib mine superintendent Mr. Zimmerman in two episodes of the 1985 mini-series
Master of the Game. Johns later appeared in the
Ken Russell films ''
Salome's Last Dance and The Lair of the White Worm (both 1988), – he can be heard on the original London cast album – and the Ghost of Christmas Present in the original Birmingham cast of the stage adaptation of the film musical Scrooge (1970), on the recording of which he can also be heard. His guest appearances on TV include The Avengers, Department S, Neverwhere, the Doctor Who serial Four to Doomsday (1982) and the Blake's 7'' episode "Games". He had a prominent role as
Calpurnius Piso in the BBC's acclaimed adaptation of
Robert Graves'
I, Claudius (1976); he played Magwitch in the BBC's 1981 adaptation of Dickens'
Great Expectations, and the jailer in
The Jail Diary of Albie Sachs. Johns appeared in the 1984 pop video for
Young at Heart recorded by The Bluebells. With him were veteran Scottish actress
Molly Weir and Scots singer/actress
Clare Grogan. In 1993, Johns appeared in the BBC period drama
Scarlet and Black alongside a young
Ewan McGregor and
Rachel Weisz. Johns played the role of Cyril Isaiah Greengrass, the conniving brother of Claude Jeremiah Greengrass in the nostalgic
Yorkshire Television series,
Heartbeat. He was also the author of the children's book
Gumphlumph; in the mid-1960s, at the height of his fame as Barlow, he read it on the children's television series
Jackanory.
Gumphlumph would be revived, again with Johns narrating, for the
TV-am children's programme
Rub-a-Dub-Tub in the 1980s. ==Personal life==