The actor was chosen by George Lucas to audition for Star Wars after seeing him in his bodyguard role in A Clockwork Orange. He could have auditioned for Chewbacca but instead he chose Darth Vader saying he chose to audition for that role because ”you always remember the bad guys."
If from the UK, perhaps you might know him for a different reason, as the Green Cross Code Man that was used to promote road safety that led to his induction in the "Member of the Most Excellent Order of the British Empire" (MBE). The actor's career never took off as he often had minor roles in other films and TV but he will always be remembered for bringing one of the most iconic cinematic characters of all time to life.