1 of 8 Doctor Who writer Russell T Davies has promised the time traveller will have a feisty, new sidekick in the series he is now developing. BBC News Online pays tribute to the doctor's former companions.
2 of 8 Anneke Wills played Polly Wright, who came on board in 1966 after a fight in London with the War Machines. She saw Hartnell regenerate into Patrick Troughton.
3 of 8 Jo Grant, played by Katy Manning, was the niece of a UN official who had assigned her to Unit, working next to Jon Pertwee's Doctor.
4 of 8 Sarah Jane Smith (Elisabeth Sladen) was a magazine journalist who became a Tardis stowaway, accompanying Pertwee and later Tom Baker.
5 of 8 Actress Sarah Sutton was Nyssa, companion to Baker and Peter Davison. She came to the Tardis after her home planet of Traken was destroyed by The Master.
6 of 8 From 1986-87, former child star Bonnie Langford was Mel Bush, introduced as a companion from the future in evidence for the defence at the Doctor's trial.
7 of 8 Grace Holloway, a cardiologist played by Daphne Ashbrook, appeared just once, in Enemy Within, the 1996 TV movie starring Paul McGann.
8 of 8 K9, most beloved of all the Doctor's companions, was a robotic dog which functioned as a mobile computer/defence system. Lovingly operated by John Leeson.