From the first actor, William Hartnell, to returning star David Tennant and the first female Doctor, Jodie Whittaker, viewers have been treated to 15 Time Lords over the years.

This month, BBC's long-running sci-fi and fantasy show Doctor Who will be celebrating its 61 year as the programme first aired back on 23 November 1963.

New colourised Doctor Who episode to show second Time Lord regeneration - Originally airing as part of the War Games story arc in 1969, the episode marked the transition between Patrick Troughton and Jon Pertwee.

Classic 'Doctor Who' episode 'The War Games' has been colourised. The seventh episode of the sixth series of the BBC sci-fi programme - which marked the final appearance of the Second Doctor (Patrick Troughton) - originally aired in black-and-white in April 1969 but has now been remastered in colour and will air on BBC Four just days before Christmas.

The BBC has announced it is releasing colourised Doctor Who footage ahead of a forthcoming special that will see a classic 1969 storyline revamped for modern screens. The BBC has announced that the Time Lord’s regeneration into the third Doctor will be aired in a new colourised version of an episode originally broadcast as part of the War Games storyline in 1969.

New BBC Doctor Who War Games episode to air second Time Lord’s 'never-before-seen' regeneration into third Doctor, as revealed on Doctor Who Day.