The Doctor is the central character in the long-running BBC television science-fiction series Doctor Who, and has also featured in two cinema feature films, a vast range of spin-off novels, audio dramas and comic strips connected to the series.
To date, eleven actors have played the role in the television series (including the 1996 television film), with these changes being explained by the ability of the character's race to regenerate. Several other actors have played the character on stage and film, in audio dramas, and in occasional special episodes of the series. The character's enduring popularity led the Daily Telegraph to dub him "Britain's favourite alien". The Doctor, in his eleventh incarnation, is currently played by Matt Smith, who took over the role from David Tennant at the end of the special The End of Time, broadcast on 1 January 2010.
The Doctor is a Time Lord, an extraterrestrial from the planet Gallifrey, who travels through time and space in an internally vast time machine called the TARDIS (Time And Relative Dimension(s) In Space).
The Doctor explores the universe at random, using his extensive knowledge of science, technology and history (from his perspective) to avert whatever crisis he encounters unless it is a fixed point in time and space. The imprecise nature of his travels is initially attributed to the age and unreliability of the TARDIS's navigation system. However, the serial The War Games, the 2009 special Planet of the Dead, as well as the 2010 finale The Big Bang reveals that the Doctor actually stole the TARDIS. He was presumably unfamiliar with its systems but was able to operate it correctly until his exile when the Time Lords wiped it from his memory. After his trial and exile to twentieth century Earth, the Doctor still visits other planets on missions from the Time Lords who pilot the TARDIS to precise locations for him. After his exile is lifted, the Doctor returns to his travels and demonstrates the ability to reach a destination of his own choosing more often than not. In "Journey's End", the Doctor states that the reason for the previous bumpy navigation was that the TARDIS is meant to have six pilots and it is also stated in "The Time of Angels" that the Doctor pilots the TARDIS with the brakes on (hence the classic noise). The Doctor generally travels with one or more companions. Most of these make a conscious decision to travel with him, but others, especially early in the series, are accidental passengers.
Read more about Doctor Who at Wikipedia ...
Official Site: BBC
Links: Wikipedia BBC-Doctor Who A biography of the Doctor