How many actors have played Doctor Who's iconic but ever-changing lead character? The answer might surprise you.

The official count is 12, or 13 if you include John Hurt's War Doctor (and why wouldn't you?), but over the years, many more actors have assumed the mantle of our favourite Time Lord.

Most fans know that Richard Hurndall replaced the late William Hartnell as the first Doctor in 1983 anniversary special 'The Five Doctors' – and that Michael Jayston and Toby Jones have both played dark, twisted versions of the Doctor (the Valeyard and the Dream Lord, respectively).

But dig a little deeper and you'll discover there are even more quasi-Doctors out there...

(Note: for the purposes of this feature, we're not counting spoofs, so no Mark Gatiss in 'The Web of Caves' or any of the marvellous folk – Rowan Atkinson, Hugh Grant et al – who featured in 'The Curse of Fatal Death'.)

1. Peter Cushing

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Related: (Doctor) Who's best? Ranking all the Doctors so far

Cushing starred in two Doctor Who movies in the 1960s – a pair of movies separate from the TV series canon, but absolutely authorised by the BBC.

1965's Dr. Who and the Daleks and 1966's Daleks – Invasion Earth: 2150 A.D. were big-screen remakes of the show's first two Dalek stories and cast Cushing not as a rogue alien but as a human inventor who'd knocked up a TARDIS in his back garden.

Even better, the name of Cushing's character actually is "Dr. Who".

Cushing also played the part a third time in the late 1960s – in a radio play, never broadcast and now sadly lost, that was intended as a pilot for a potential series. Interestingly, he was also considered to play both the second Doctor and the fourth on television. What might've been...

2. Trevor Martin

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Doctor Who and the Daleks in the Seven Keys to Doomsday – more commonly known as just Seven Keys to Doomsday – was a stage play that ran at London's Adelphi Theatre for a month in late 1974.

Trevor Martin, who'd previously played a Time Lord on the TV series, was cast as the Doctor, with Wendy Padbury, Patrick Troughton's assistant Zoe on telly, playing a new companion character named Jenny.

The script, written by former Doctor Who script editor Terrance Dicks, charted the Daleks' attempts to take over the universe with the help of crab-like slaves, known as "Clawrantulars" – superb.

3. Adrian Gibbs

BBC

Related: Who is the First Doctor? Everything you need to know about Doctor Who's original Time Lord

Tom Baker's final Doctor Who outing saw him haunted by a wraith-like figure known as the Watcher. Eventually revealed as a manifestation of the Doctor himself, the Watcher fused with an injured fourth Doctor to enable his next regeneration at the close of 1980's 'Logopolis'.

The part was played, uncredited, by Adrian Gibbs, who'd previously played the part of Rysik opposite Baker in the same year's 'Full Circle'.

4. Richard E Grant

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Grant actually first played the Doctor in 1999's Comic Relief spoof The Curse of Fatal Death, written by none other than Steven Moffat (see our intro above).

But he would play an entirely different incarnation four years later, in the animated webcast 'The Scream of the Shalka'.

At the time, this six-part series – also starring Sophie Okonedo as companion Alison Cheney, and Derek Jacobi as The Master – was considered an official continuation of the television series, with Grant being billed as the bona-fide ninth Doctor.

However, once the show returned to TV in glorious live-action in 2005 – with Christopher Eccleston firmly established as Doctor no. 9 – the 'Shalka' Doctor was swept under the carpet, with all plans for further webcasts abandoned.

5. David Banks

Mark Furness Ltd/British Broadcasting Corporation

Related: Every single 'new' Doctor Who episode ranked from 'Rose' onwards

Another stage play – again written by Terrance Dicks – The Ultimate Adventure toured twenty theatres from March 1989, towards the end of the TV show's original run.

Jon Pertwee played the Doctor until June of 1990, with Colin Baker replacing him for the play's final few months. But notably, understudy David Banks stepped up to play the Doctor for two performances when Pertwee was ill.

Banks is also known to Doctor Who fans for playing the Cyberleader in four television stories: 'Earthshock' (1982), 'The Five Doctors' (1983), 'Attack of the Cybermen' (1985) and 'Silver Nemesis' (1988).

6. John Guilor

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Guilor played the first Doctor in 2013's 50th anniversary special 'The Day of the Doctor' – though you'll have only have heard, rather than seen, the voice-over artist.

His uncanny William Hartnell impersonation features in the scene where all 13 Doctors team up to save their home world: "Calling the war council of Gallifrey – this is the Doctor!"

Guilor's imitation is so on-point, you might assume the episode had used archive audio of Hartnell – except that the Doctor's planet was first named in 1974, some eight years after the first Doctor's era had ended.

7. The Unbound Doctors

Big Finish

Related: Here's what Doctor Who would have looked like if the intended actors had been cast

Tom Baker, Peter Davison, Colin Baker, Sylvester McCoy, Paul McGann, John Hurt and David Tennant have all appeared in the Doctor Who audio plays, produced by Big Finish and sanctioned by the BBC.

But, beginning in 2003, Big Finish also released a series of side-step adventures, exploring 'What If?' questions in the world of Doctor Who. What if the Doctor never left Gallifrey? What if (gasp!) the Doctor was a woman?

Doctor Who Unbound cast Geoffrey Bayldon, David Warner, David Collings, Arabella Weir and Derek Jacobi (him again!) as all-new versions of the Doctor, in stories that veered from the surreal to the disturbing.

8. The Morbius Doctors

BBC

In 1976 Tom Baker story 'The Brain of Morbius', the fourth Doctor engages in a literal battle of wits with the titular villain. Morbius uses a 'mind-bending' device to do battle – and as he faces off against the Doctor, past incarnations of the Time Lord appear on the machine's display.

But there's a twist. Eight faces appear on the screen preceding Hartnell's first Doctor – which some fans have taken to be pre-Hartnell incarnations (which was indeed the intention of the production team at the time).

"It is true to say that I attempted to imply that William Hartnell was not the first Doctor," said producer Philip Hinchcliffe. "We tried to get famous actors for the faces of the Doctor – but because no-one would volunteer, we had to use backroom boys."

Hinchcliffe himself appears in the sequence, along with production unit manager George Gallaccio, script editor Robert Holmes, production assistant Graeme Harper, director Douglas Camfield, production assistant Christopher Baker, writer Robert Banks Stewart, and director Christopher Barry.

This being Doctor Who, it's 40 years later and fans are still debating the veracity of the 'Morbius' Doctors. (Canonical or not, we love their headgear and natty facial hair.)

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