William Hartnell (1963-66)
Irascible old codger dragging his insouciant grand-daughter round time and space (Aha! So The Doctor has done it at least once!) The model of the aged scientist being looked after by a lone daughter or grand-daughter was something of a template by this time, having appeared in Forbidden Planet and other films.

The conceit seems to have been that the daughter represents the humanising conscience of amoral science. Since Carol Ann Ford wanted out and the Doctor didn’t have an unlimited supply of grand-daughters, she was replaced by a continuing run of (mostly) female assistants. Many of the Hartnell Whos were erased forever, though efforts continue to recover them, mostly from foreign archives.

Patrick Troughton (1966-69)
Cosmic hobo. Equally mercurial but slightly less grumpy, flute-playing Troughton developed a gentler side to the time lord that Jon Pertwee would go on to make a primary characteristic. Once again, a huge number of episodes are lost from Troughton’s tenure.

Jon Pertwee (1970-74)
Dandy. Exiled to Earth by the Time Lords for his interfering ways, Pertwee was stuck with those stuffy UNIT chaps for pretty much his entire time as The Doctor. The smoking jacket and opera cloak marked him out as an aesthete, and his impeccable manners and decorum may owe a little to Peter Cushing’s kindlier film roles (Cushing himself played The Doctor twice, see end of article). Where the Doctor’s characteristic diplomacy failed, Pertwee was the first to wade in, with a knack for then-trendy karate that did not seem to follow The Doctor into later incarnations.

Tom Baker (1974-81)
Madman. The most recognisable and iconic face of Doctor Who, he started out all jelly babies and mad Cheshire-cat grins, but could be very short-tempered and moody even with his beloved Sarah Jane. Baker’s Doctor immediately dumped the UNIT bores and Bessie - Pertwee’s jalopy - to set back off in adventures in time and space, many of which were inspired by the very popular Hammer films which were showing on a weekend loop in the 1970s. Thus Baker’s Doctor met the equivalent of Frankenstein, Dracula, Fu Manchu and many other schlock-horror stalwarts, as well as starring in possibly the best Who story ever, Genesis Of The Daleks.

Peter Davison (1981-84)
Public school prefect. Davison’s non-descript character and beige ‘cricketer’ tones were a shock after the eccentric extremes of Baker, and to be fair, he couldn’t have had a harder act to follow. Chosen as a younger Doctor that would be immediately recognisable to the public, due to his stint as Tristan in the popular All Creatures Great And Small, Davison was hardly ever off the screen for the first half of the eighties, arguably over-exposed. Davison’s Doctor was frequently brusque and impatient, and seemed to have a veritable herd of assistants to dilute any accusations of impropriety!

Colin Baker (1984-86)
Colin Hunt. What the worst Doctor ever did to deserve the sexiest Doctor Who assistant ever is one of Gallifrey’s darkest mysteries, but Peter Davison nonetheless surrendered Peri (Nicola Bryant) to C Baker’s abrasive buffoon in 1984. Colin’s tenure marked a low point for the quality of writing in the series, and the clownish colours of his costume were both a sadly empty invocation of the Tom Baker era and a stark contrast to this new incarnation’s saturnine personality, which was later redeemed in a series of radio plays that Colin Baker undertook as his Doctor in the late nineties. Once Peri was replaced by Bonnie Langford, there seemed little reason left to watch the show.

Sylvester McCoy (1987-89)
Whimsical Oxford don. Diminutive but disarming comedian and actor McCoy had the reverse luck to Peter Davison, as Colin Baker proved a very easy act to follow. With toned-down dress-sense but retaining a more palatable brand of eccentricity, McCoy’s Doctor travelled his space-time adventures in the company of the popular and streetwise Ace (Sophie Aldred), and is probably the least physical and most diplomatic Doctor since Tom Baker. Fans were relieved to have someone they could like in the role again, and the fact that his well-intentioned devious stratagems extended even to his beloved assistant gave this incarnation a welcome sense of mystery.

Paul McGann (1996)
Lord Byron after therapy. McGann’s Victorian poet was a sexier, younger Doctor intended to kick-start a new series on the Fox network. Despite popular reception in the UK, poor marketing is blamed for the pilot’s failure in the essential stateside market, and this first re-boot fizzled out after the single 90-minute ‘telemovie’. Thought by casual Who fans to have had one single stab at the role, McGann has actually played the Eighth Doctor many times in subsequent radio dramas, and his incarnation is one of the most rendered in comics, audio and novels.

Christopher Eccleston (2005)
Grinning man in a leather jacket. Ecclestone – who lobbied for the newly-revived role only to abandon it after one season – registered only two notes as the ninth Doctor: grinning annoyingly and showboating. If you are going to grin that much for no reason, you had better be as charming and fascinating as Tom Baker, and unfortunately Eccleston was not.

David Tennant (2006 - )
Influential big brother. Pretty boy and very accomplished actor Tennant made only one mistake in interpreting the tenth Doctor, but unfortunately it was a doozey: he kept too many of Eccleston’s annoying characteristics, including the grandstanding sermons and the inane grinning. Despite this, he is among the most credible of the action-hero Doctors, with genuine gravity and presence, as well as good comic timing that is not always well-served by the quality of the jokes. Those impressed to see that Tennant has knocked Tom Baker off the top spot of ‘Favourite Doctors Of All Time’ in polls might be advised to play the longer odds, since Sylvester McCoy also managed this trick at the end of his tenure in 1990.

Extra Doctors

Peter Cushing
Cushing was a shoe-in to play The Doctor at some point, although his appearance in the films Doctor Who And The Daleks and Daleks: Invasion Earth 2150 AD present the character as a human inventor rather than a Gallifrean time lord. The Daleks are brightly coloured and the presence of Roy Castle and/or Bernard Cribbins was an ill-omen. The character also referred to himself as ‘Doctor Who’.

Richard E. Grant
He’s not going to understudy anybody! Withnail joined ‘I’ in the role, playing the ‘unofficial’ ninth doctor in the Flash-based webcast Scream of the Shalka. News of the show’s TV revival stole the thunder from this low-budget attempt to continue the series, and the worst news was that Grant either didn’t get offered or didn’t want to take his role to TV.

Many other actors have performed the role in audio, on stage and on the web.See here for a fairly complete list.