Anjelica Huston Vivanne Actor Julianna Margulies Morgaine Actor Joan Allen Morgause Actor Samantha Mathis Gwenwyfar Actor Caroline Goodall Igraine Actor Edward Atterton Arthur Actor Michael Vartan Lancelot Actor Michael Byrne Merlin Actor Hans Matheson Mordred Actor Mark Lewis Jones Uther Actor Clive Russell Gorlois Actor Tamsin Egerton Young Morgraine Actor Christopher Fulford Lot Actor David Calder Uriens Actor Hugh Ross Bishop Patricius Actor Edward Jewesbury Ambrosius Actor Freddie Highmore Young Arthur Actor Uli Edel Director Gideon Amir Producer Mark Wolper Executive Producer Bernd Eichinger Producer Lisa Alexander Executive Producer James Coburn Executive Producer Gavin Scott Writer