His birth name was Anthony Robert McMillan, but changed it in his early career years in honor of the well-known, well-respected jazz saxophonist John Coltrane.
Perhaps best known for his role as the excessive and obsessive forensic psychologist Eddie "Fitz" Fitzgerald in the 1990s British TV series 'Cracker', he also was known for his work in several James Bond movies, and as Rubeus Hagrid in eight Harry Potter films. His theatrical history was substantial, having appeared in more than 40 movies and about 40 television shows.