He got a big break in Harry's Game, where he played the lead IRA gunman on the run following the assassination of a government minister.
Later he played another IRA hitman in the TV series The Price and for a British mercenary gang in the Wild Geese II, both filmed in 1985.
During the same period, Thompson had minor film roles in Yanks (1979) and Breaking Glass (1980), and also played Jeff, Harold Shand's lieutenant, in the box office hit movie The Long Good Friday.
The following year he met his future wife, Dee Sadler, an actress playing the role of Maggie in an episode of the show's second series, a potholer who had to be rescued from a cave before hospitalisation.
[2] In 2023, it was announced that after 38 years, Thompson would be leaving Casualty; his exit aired in March 2024, at the conclusion of a special two-part episode.