Sophia Myles played Jeanne-Antoinette Poisson in the Doctor Who story The Girl in the Fireplace. Prior to her appearance on Doctor Who, she was best known for appearing in costume dramas: she appeared in Underworld and as Lady Penelope in the remake of Thunderbirds, along with Ron Cook as Penelope's Driver, Parker. Myles also starred as Isolde in Tristan + Isolde and as Kate Breck in Hallam Foe.
Before she starred in Doctor Who, she was romantically involved with her The Life and Adventures of Nicholas Nickleby co-star Charles Dance, thirty-four years her senior.
During filming of The Girl in the Fireplace, she began dating David Tennant and the relationship continued for two years.[source needed] During this period, she assisted the Doctor Who production crew by reading the role of Donna Noble at the cast run-through for The Runaway Bride (Catherine Tate was not available). She also helped Tennant record some of his video diaries for the DVD box sets, appeared in a couple of them and also handled the camera.
The relationship between Myles and Tennant reportedly ended[source needed] around the time she relocated to America to co-star in the 2007-08 series Moonlight, which was cancelled after one season. Also around this time she appeared in the film Art School Confidential.
Like Tennant, she also appeared in an episode of Extras.
She also contributed to the charity reference book Behind the Sofa: Celebrity Memories of Doctor Who.