10 Actors With Multiple Roles In Doctor Who
8. Eve Myles
First Role: Gwyneth (The Unquiet Dead)
Second Role: Gwen Cooper (Torchwood)
One of the very first guest actors to appear in the revived series of Doctor Who, Eve Myles first appeared in 2005's The Unquiet Dead - the third episode of Christopher Eccleston's sole season - as Gwyneth, a servant who possessed the ability to communicate with gaseous ghosts (and villains of the week) the Gelth.
Gwyneth ended up dying at the end of this story, but Myles' Doctor Who career was far from over. In 2006, she starred as female lead Gwen Cooper in Torchwood, which ran for four popular seasons and concluded in 2011.
Along the way, Myles also appeared in Doctor Who for a second time too, playing Gwen (and battling Daleks) in 2008's series finale The Stolen Earth and Journey's End.
In the latter episode, an explanation was offered for why Gwen and Gwyneth look identical, despite existing over a hundred years apart: after noticing Gwen, the Doctor remarks that "spatial genetic multiplicity" is responsible for their clone-like looks.
According to then-showrunner Russell T Davies, this means that Gwen and Gwyneth do not share a bloodline. Rather, Gwen's appearance is the result of an "echo" through time, one that emanated from Gwyneth all those years ago.