Tegan: And who might you be?
First Doctor: I might be any number of things, young lady. As it happens I am the Doctor. The original, you might say.

Tegan and the First Doctor (played by Richard Hurndall)

The Five Doctors

Doctor Who In Detail is a guide to the long running BBC Television programme Doctor Who. The first episode was broadcast in 1963, and the programme celebrated its 50th anniversary in 2013, making Doctor Who the longest running science fiction television programme.

So far twelve actors have portrayed the role of the Doctor (or thirteen if you count John Hurt as the War Doctor) in the televsion series (excluding stand-ins), with Peter Capaldi soon to appear in his third series in 2017.

On TV today 4 December 2016

New Earth 3:00 pm - 4:00 pm W (HD)
David Tennant takes over full time as the heroic Time Lord. The Doctor and Rose find dark secrets hidden inside a hospital, where paper-thin Cassandra plots revenge. S31 Ep1
Tooth and Claw 4:00 pm - 5:00 pm W (HD)
A spine-tingling adventure for David Tennant's Time Lord. In 1879, the Doctor and Rose meet Queen Victoria in Scotland. But who's the hairy chap? S31 Ep2
School Reunion 5:00 pm - 6:00 pm W (HD)
Robot dog K9 and former companion Sarah Jane Smith here team up with David Tennant's Time Lord. A London school is haunted by strange bat-creatures at night. S31 Ep3
The Girl in the Fireplace 6:00 pm - 7:00 pm W (HD)
David Tennant stars in a haunting episode of Britain's favourite sci-fi series. The court at Versailles is under attack from clockwork killers. S31 Ep4
For a full list of tv programmes view the tv guide here.

On this day 4 December

1965: The Daleks' Masterplan: The Traitors: The TARDIS materialises on the planet Kembel several months after the death of Marc Cory
1992: The Dæmons: Episode Three: The Master summons a daemon, Azal, in the hope of receiving Azal's powers
2007: Fear Her: A girl breathes in a spore and gains the ability to make people disappear
2015: Heaven Sent: The Doctor is trapped in his own nightmare. The only way out is to confess.