Aged 9, Valentine was spotted tap-dancing in a stage version of Robin Hood at Ealing Town Hall. He made his acting debut at age 10 in the Nettlefold Studios film No Way Back (1949), and at age 12 he was a boy sleuth in The Girl on the Pier (1953). He worked regularly as a child actor for the BBC, most notably as Harry Wharton in the 1950s adaptation of Billy Bunter of Greyfriars School, having initially played Lord Mauleverer in earlier episodes.
Valentine's early stage credits include: the premiere of Arnold Wesker's Chicken Soup with Barley (Royal Court Theatre, 1958); John Osborne's Epitaph for George Dillon (Royal Court Theatre, 1958); Australian drama The Shifting Heart (Duke of York's Theatre, 1959, with Leo McKern); John Mortimer's Two Stars for Comfort (Garrick Theatre, 1962, with Trevor Howard); the original cast of Half a Sixpence (Cambridge Theatre, 1963, with Tommy Steele); and The Platinum Cat (Wyndham's Theatre, London, 1965, with Kenneth Williams).
Valentine was best known for his striking performances in particular television roles: ruthless Toby Meres in the series Callan (1967–72), sinister Luftwaffe officer Major Horst Mohn in the BBC drama Colditz (1974), the dashing eponymous role in Yorkshire TV's Raffles (1975-1977), and suave crook George Webster in The Knock (1994–96). Selected television and film credits are listed below.
Later stage credits include: No Sex Please We're British (Strand Theatre, 1971); Anthony Shaffer's Sleuth (St Martin's Theatre, 1972, with Marius Goring); a revival of Hans Christian Andersen (London Palladium, 1977, again with Tommy Steele); 'Art' (Wyndham's Theatre, 1999-2000); and he played Cardinal Monticelso in Webster's The White Devil (Lyric Theatre, 2000).
Interviewed in 1995, Valentine recalled two earlier brushes with death. First, struck down at age 36 by meningitis; second in 1974, when caught up in the Turkish invasion of Cyprus, holed up in a holiday hotel as gunfire raged outside. "I've always felt that everything since has been an incredible bonus," he said.
Valentine made his debut as a Writer and Director in 1998 at The Mill at Sonning with The Waiting Game. He went on to direct regularly at the Mill, productions including: Separate Tables (2005), The Odd Couple (2009) and California Suite (2012). On 12 November 2005 Valentine became a patron of the Thwaites Empire Theatre in his birthplace, Blackburn.
Valentine died at the age of 76 on 2 December 2015 in Guildford, Surrey, having suffered from Parkinson's disease for several years. He was survived by his wife, Actress Susan Skipper. The couple married in 1982, having met on Raffles, and appearing together again in a television film of Ivor Novello's show The Dancing Years (1976).
