Dr Who - Ultimate Time Traveller

David Tennant (born David John McDonald; 18 April 1971) is a Scottish actor. Already a theatre actor, Tennant is also known for his roles in Doctor Who as the Doctor, in Casanova, and as Barty Crouch, Jr. in Harry Potter and the Goblet of Fire.

Doctor Who is a British science fiction television programme produced by the BBC. The programme depicts the adventures of a mysterious alien time-traveller known as "the Doctor" who travels in his space and time-ship, the TARDIS, which normally appears from the exterior to be a blue 1950s police box. With his companions, he explores time and space, solving problems, facing monsters and righting wrongs.

The programme is listed in Guinness World Records as the longest-running science fiction television show in the world and is also a significant part of British popular culture. It has been recognised for its imaginative stories, creative low-budget special effects during its original run, and pioneering use of electronic music (originally produced by the BBC Radiophonic Workshop). In the United Kingdom and elsewhere, the show has become a cult television favourite and has influenced generations of British television professionals, many of whom grew up watching the series. It has received recognition from critics and the public as one of the finest British television programmes, including the BAFTA Award for Best Drama Series in 2006.

The programme originally ran from 1963 to 1989. After an unsuccessful attempt to revive regular production with a backdoor pilot in the form of a 1996 television film, the programme was successfully relaunched in 2005, produced in-house by BBC Wales in Cardiff. The first three seasons of the new series had some development money contributed by the Canadian Broadcasting Corporation (CBC), which was credited as a co-producer. Doctor Who has also spawned spin-offs in multiple media, including the current television programmes Torchwood and The Sarah Jane Adventures, and a single 1981 pilot episode of K-9 and Company.

The show's protagonist, the Doctor, has been played by ten actors over the history of the show so far. The transition from one actor to another is written into the plot of the show as regeneration, and the different parts are often treated as distinct characters to the extent that in some time travel plots they encounter one another and work together. The Doctor is currently portrayed by David Tennant. In the programme's most recent series, which ran from 5 April to 5 July 2008, Catherine Tate played the Doctor's companion, reprising her role of Donna Noble from the 2006 Christmas special. A Christmas special, entitled "The Next Doctor", was broadcast in 2008 and will be followed by four more specials in 2009 and early 2010. The first of these was an Easter special titled "Planet of the Dead", which broadcast in April 2009, and the next one is called "The Waters of Mars"; the next full series, Series 5, has been confirmed to air in 2010. Tennant announced at the 2008 National Television Awards that after appearing in the four 2009?2010 Doctor Who specials, he will leave the role. The Eleventh Doctor will be portrayed by Matt Smith. Smith was 26 years old at the time of his casting, making him the youngest actor to be cast in the role. Karen Gillan, who played a soothsayer in the episode "The Fires of Pompeii", will play the Eleventh Doctor's companion.

Billie Piper (born Lianne Paul Piper on 22 September 1982) is an English singer and actress.

She began her career as a pop singer when she was a teenager and progressed to acting; her roles include Rose Tyler, companion to the Doctor in the television series Doctor Who from 2005 to 2006, a role she reprised in 2008. In 2007, Broadcast magazine listed Piper at #6 in its "Hot 100" list of influential on-screen performers, the top woman on the list. She has also portrayed the prostitute Belle de Jour in Secret Diary of a Call Girl.