Williams's professional career began in 1948 in repertory theatre. Failure to become a serious dramatic actor disappointed him, but his potential as a comic performer gave him his break when he was spotted playing the Dauphin in Bernard Shaw's "St Joan" in the West End, in 1954 by radio producer Dennis Main Wilson. Main Wilson was casting "Hancock's Half Hour", a radio series starring Tony Hancock. Playing mostly funny voice roles, Williams stayed in the series almost to the end, five years later. His nasal, whiny, camp-cockney inflections (epitomised in his "Stop messing about ... !" catchphrase) became popular with listeners. Despite the success and recognition the show brought him, Williams considered theatre, film and television to be superior forms of entertainment. In 1955 he appeared in Orson Welles's London stage production "Moby Dick—Rehearsed". The pair fell out after Williams became annoyed with Welles's habit of continually changing the script.