Above Two series indelibly tied to Brian Clemens: The Avengers, for which he wrote and produced, and The Professionals, which he created, regularly wrote and executive produced.

British screenwriter Brian Clemens, OBE, passed away on Saturday, sources say.
   Clemens was the creator of the cult 1970s LWT show The Professionals, with a string of credits to his writing career including The Avengers, The Persuaders, The Protectors, Bergerac, Diagnosis: Murder and Bugs. He also created the German show Blaues Blut (Blue Blood) in the 1980s.
   Brian Horace Clemens was born in Croydon in 1931, and was a weapons’ training instructor during his National Service. He wanted to be a journalist but began his career at J. Walter Thompson as a messenger, before becoming a copywriter. During this time a screenplay of his that he had sent to the BBC, Valid for Single Journey Only, had been accepted and produced in 1955 and starred Ernest Clark and George Colouris.
   Clemens wrote for B-movies and half-hour serials made by the Danziger brothers in the mid- to late 1950s, including Mark Saber, White Hunter, The Man from Interpol and Richard the Lionheart. The Vise and Dial 999 were also from this period, with Clemens using the pseudonym Tony O’Grady around this time.
   In the 1960s, Clemens’ scripts were made by various ITC shows, including The Invisible Man, Man of the World, The Sentimental Agent and The Champions, and he wrote the pilot for Danger Man. He also wrote the pilot for The Avengers, where he was script editor and associate producer, and he was responsible for casting Diana Rigg as Emma Peel. He wrote for The Baron, and he penned the pilot for The Persuaders. Some of the last ITC action series such as The Protectors and The Adventurer also saw Clemens scripts.
   In the 1970s, Clemens created a sitcom, My Wife Next Door, and wrote a US TV movie, The Woman Hunter. He also wrote the anthology series Thriller for ITV, Dr Jekyll and Sister Hyde, a 1971 Hammer horror, The Golden Voyage of Sinbad in 1973, and wrote and directed Captain Kronos, Vampire Hunter in 1974.
   The Avengers was revived in 1976 was The New Avengers, earning Clemens a new generation of fans. As executive producer, he had cast Joanna Lumley as Purdey. In response to Thames’s The Sweeney, Clemens created and produced The Professionals for LWT, which proved to be the series he is most associated with. A TV movie, Escapade, was made in 1978, and meant to have been a pilot for a US version of The Avengers.
   In the 1980s, Clemens wrote for Remington Steele, Bergerac, Worlds Beyond, The Father Dowling Mysteries (where he served as executive story editor), and Perry Mason. In the 1990s, Clemens wrote for Diagnosis: Murder, Bugs, The Highlander TV series (he had also co-written Highlander II: the Quickening), and a revival of The Professionals, entitled CI5: the New Professionals. Attempts to revive The Professionals as a feature film were not realized, although The Avengers was shot as a Hollywood movie in 1996, starring Ralph Fiennes, Uma Thurman and Sean Connery.
   Clemens also wrote numerous plays, beginning with a stage adaptation of The Avengers in 1971, and continued until 2012 with Murder Weapon.
   Clemens and his wife, Brenda, divorced in 1966. He was with the actress Diane Enright till she committed suicide in 1976. He married his second wife Janet in 1979, and they had two children. He was awarded the OBE in 2010.
   Brian Clemens was related to Samuel Clemens, a.k.a. Mark Twain.