Guest Stars Lena Headey as Guinevere Sebastian Roché as Gawain Daniel Brocklebank as Young Merlin Roger Ashton-Griffiths as Sir Boris Peter Woodthorpe as Soothsayer Vernon Dobtcheff as 1st Physician Jason Done as Mordred Justin Girdler as Young Galahad Emma Lewis as Elissa Talula Sheppard as Lady Friend Rachel Colover as Lady Igraine Alice Hamilton as Young Morgan le Fay John Turner as Lord Lot Janine Eser as Lady Elaine Agnieszka Kozon as Young Nimue Nicholas Clay as Lord Leo John McEnery as Lord Ardente Keith Baxter as Sir Hector Billie Whitelaw as Ambrosia Paul Curran as Arthur John Tordoff as New Architect Peter Benson as 1st Architect Mark Jax as Uther Pendragon Nickolas Grace as Sir Egbert Peter Eyre as Chief Physician Robert Addie as Sir Gilbert Thomas Lockyer as Cornwall Peter Bayliss as 2nd Physician Timothy Bateson as Father Abbot Jeremy Sheffield as Lancelot