Alun was a member of the original London cast of Cameron Mackintosh's stage production "Les Miserables" which opened in 1985.
Father of Joe Armstrong. The two of them appeared in the TV series 'Between The Sheets'.
He attended Consett Grammar School in County Durham
He has appeared in seven different adaptations of one of Charles Dickens's novels: "The Life and Adventures of Nicholas Nickleby" (1982), "Oliver Twist" (1999), David Copperfield (1999) (TV), "Bleak House" (2005), Oliver Twist (2005), "Little Dorrit" (2008) and "The Mystery of Edwin Drood" (2012).
He has appeared in two versions of "Oliver Twist", and played a different role in each.
He was awarded the Laurence Olivier Theatre Award in 1994 (1993 season) for Best Actor in a Musical for his performance in Sweeney Todd at the Royal National Theatre.