Edge of Darkness, the 1985 BBC serial written by the Z Cars creator Troy Kennedy Martin, changed the course of Peck's career and his life - at the age of 40. Until then, most of his time had been spent on stage, including nine years with the Royal Shakespeare Company.
The six-part thriller, in which Peck played a Yorkshire police detective investigating his own daughter's murder, became one of the most talked- about programmes of the 1980s and the corporation's fastest repeat when BBC1 started a rerun just 10 days after it had finished on BBC2. Its story of government collusion in the production of plutonium at a secret nuclear plant struck a chord two years after President Reagan's "Star Wars" speech, at a time when people were beginning to question Britain's alliance with America.
Despite this exposure, and a Bafta Best Actor award, Peck ruminated that he could "still shamble round Sainsbury's looking as nondescript as the next man" and insisted that he simply wanted to be seen as "someone who is able to play a character and make him look ordinary". He continued to do so in a thoroughly accomplished manner through more than two dozen screen roles and further stage performances with the National Theatre and Young Vic companies.
It was a career to which Peck, born in 1945 and brought up in Leeds, had been drawn at school. At the age of 15, he joined the National Youth Theatre in London but described himself as "completely unhappy and lonely" during the six-week experience, putting it down to his inability to mix with people.
However, he still enjoyed acting and, while studying at Leeds College of Art, performed in amateur dramatics. After the playwright Alan Ayckbourn directed the society in a production of his play Mr Whatnot, he invited the teenager to spend the summer as an actor and assistant stage manager at the Scarborough Library Theatre, of which he had just become artistic director.
Ayckbourn recalled discovering "an actor of strength, extraordinary natural technical ability, wit and truth". As a result, Peck made his professional acting debut in Scarborough and subsequently performed in repertory theatre in Exeter.
Returning to London, in 1974, he landed a part in Lindsay Anderson's production of Life Class, by the Wakefield miner's son David Storey. The play, which drew on Storey's own experience of art college, opened there before transferring to the West End. Peck was clearly on his way and, after a spell at Birmingham Rep, he joined the Royal Shakespeare Company at Stratford-upon-Avon for a nine-year stint (1975-84) during which his roles included Macbeth, Iago, Kent, Malvolio, Caliban and Lear, and he worked with directors such as Ronald Eyre and Trevor Nunn.
While with the RSC, Peck made his first screen appearances. He could be seen credited simply as "Customer" in the Ronnie Barker sitcom Open All Hours and as "Ron" in an episode of Rising Damp. More significantly, he acted in Alan Bennett's television play Sunset Across the Bay (1975), directed by Stephen Frears, and played Macduff in a television production of Macbeth (1979), repeating one of his RSC roles.
He also gained film experience as a police inspector in Royal Flash (1975) and a minister in Bird of Prey 2 (1984). His two contrasting roles in the celebrated RSC four-act, nine-hour production of Charles Dickens's "Yorkshire novel", Nicholas Nickleby (1981) - John Browdie and Sir Mulberry Hawk, the hero and the villain - were seen in the television film The Life and Adventures of Nicholas Nickleby (1982), screened in Channel 4's first weeks on the air.
Having married the actress Jill Baker and started a family, Peck decided to leave the security of the RSC to seek more television roles, partly in the hope of spending more time with his family. "I realised I could stay there for a long time and I would never know whether I could have made it as a TV or film actor," he explained.
He was fortunate enough to walk into the part of single-parent Detective Inspector Ron Craven in Edge of Darkness, alongside Joanne Whalley as his radical scientist daughter Emma. Troy Kennedy Martin had envisaged John Thaw in the starring role. But the director, Martin Campbell, favoured an unknown actor and opted for Peck. The actor's brother was, in fact, a policeman in Leeds, but Peck spent two days with the Bradford force in the course of his research to see how they worked.
However, he refused to mutate into a radiation-ravaged tree over hundreds of years after falling to a sniper's bullet, as the end of Kennedy Martin's script demanded. Peck won the argument and, instead, screamed his daughter's name, "Emma!"
The serial, whose prophesies included a Gulf War, was watched by 4.5 million viewers on BBC2 and 8 million on BBC1. As well as winning Peck a Best Actor award from Bafta, Edge of Darkness was presented with the Best Drama honour.
Although Peck returned to the stage by starring at the National Theatre in Alan Ayckbourn's A Chorus of Disapproval and Athol Fugard's The Road to Mecca (both 1985), offers to act on screen followed thick and fast.
Most notably, he played a repressed don in Simon Gray's television play After Pilkington (1987) and Dante in Channel 4's A TV Dante: the Inferno cantos I-VIII (1989), directed by Peter Greenaway and Tom Phillips, starring John Gielgud and reuniting Peck with Joanne Whalley. Other parts included a doctor rejected by the woman he loves in Children Crossing (1989), a Royal Marines major in the Falklands in An Ungentlemanly Act (1992), Gradgrind in Peter Barnes's adaptation of Hard Times for BBC Schools (1994) and Shylock in The Merchant of Venice (1996).
As in Edge of Darkness, an "awkward" theme was explored when Peck played a man whose cosy life with a new girlfriend is shattered when he is menaced by his estranged wife's lover in Mick Ford's One Way Out (1989). He made significant contributions to Catherine Cookson's The Black Velvet Gown (1991), as a reclusive former teacher who gains a hold on his widowed housekeeper, Centrepoint (1992), in the rare role of a villain, Natural Lies (1992), acting a happily married man who discovers that his first love has killed herself in mysterous circumstances, and The Scold's Bridle (1998), once again playing a detective.
Peck also found himself in demand with film directors for both starring and cameo roles, although his best pictures were mostly those in which he took the lead. In the writer-director Andrew Grieve's much admired production of On the Black Hill (1987), based on Bruce Chatwin's novel, Peck was in his best "dour" mode as the puritanical Welsh-farmer husband of a woman who has stepped down the social scale to marry him.
The finely observed drama The Kitchen Toto (1987) featured Peck as a British chief of police during the final years of colonial rule in Kenya in the Fifties, while Steven Spielberg cast him as the game warden Robert Muldoon in the dinosaurs yarn Jurassic Park (1993).
More disappointingly, he acted in pictures such as the science-fiction drama Slipstream (1989), a Lord of the Flies remake (1990), Surviving Picasso (1996, alongside Anthony Hopkins) and Smilla's Feeling for Snow (1997, from Peter Hoeg's best-selling novel).
In between film and television work, Peck returned to the stage in director David Thacker's productions of two Arthur Miller plays at the Young Vic Theatre - Two Way Mirror (1989), with Helen Mirren, and The Price (1990), alongside David Calder - was directed by Jack Shepherd as revolutionary Tom Paine in In Lambeth (1989) at the Donmar Warehouse, and played Goldberg in Sam Mendes's National Theatre production of Harold Pinter's The Birthday Party (1994). Also at the National in 1994, he played the overbearing patriarch John Rutherford in Githa Sowerby's 1912 Rutherford and Son, as a "north-country Lear, craggy, ruthless and utterly self-centred"; Paul Taylor in The Independent described his performance as "magnificently overbearing and authentic".
Robert Peck, actor: born 23 August 1945; married 1982 Jill Baker (one son, two daughters); died Kingston-upon-Thames, Surrey 4 April 1999.