 John Boorman wanted the story to be the focus of the movie rather  than the actors. Therefore, he cast actors that were relatively  unknown at the time to American audiences. Among them were Gabriel  Byrne (Uther), Patrick Stewart (Leondegrance), Liam Neeson (Gawain),  Helen Mirren (Morgana), and Nicholas Clay (Launcelot). Only Nicol  Williamson (Merlin) was relatively familiar to American moviegoers.