Doctor Who has run, on and off but mostly on, for more than fifty years. A key way its achieved this longevity is through recasting its lead actor every few years. Almost exactly the same thing is true, of course, of James Bond – and many other long-running television shows or film series. But Doctor Who differs in that the recasting of the series' lead is referenced within the fiction. The series becomes about the character changing their face, if only for the new Doctor's first story.

A changeover of Doctors is a great opportunity for the series to attract new viewers and win back lapsed ones, to change direction and renew itself creatively. It's also the moment of maximum danger for a series that depends hugely on the popularity of its lead actor and their interpretation of the role. With Thirteenth Doctor Jodie Whittaker about to make her debut on Sunday, here's a look back at how previous Doctors debuts have been handled and received.

“An Unearthly Child”

23 November 1963 - 14 December 1963

The first episode of Doctor Who was transmitted the day after the assassination of John F Kennedy, to a shell-shocked audience. Very few people were watching, and it’s likely that a lot of people who remember watching the first episode of Doctor Who actually saw it seven days later. Producer Verity Lambert convinced her BBC superiors to allow a repeat of the first episode the following week, so wholly had her launch been derailed by the news.

William Hartnell had a far more traditional job as the Doctor than any of his successors. He was simply an actor cast in a part that existed in some scripts, not someone taking over a role via an in-fiction explanation and physical metamorphosis. Six weeks after Doctor Who’s uneasy start, the Daleks appeared for the first time and it became a hit, with audiences in excess of ten million. By early 1965 episodes were being seen by 13 million viewers – about a quarter of the population – regardless of whether they featured Daleks.

It’s worth noting to those who feel the casting of Jodie Whittaker as Hartnell’s most recent successor is an example of enforced diversity, that the earliest episodes of this most ostensibly British television programme, which was created by a Canadian, were written by an Australian, directed by a Lucknow-born Muslim and produced by Lambert who, while a nice well-brought up, private school sort from north London, suffered in establishment eyes from being both female and Jewish.

“The Power of the Daleks”

5 November - 10 December 1966

Three years after the programme’s debut, and eleven months after a ratings crash, the reasons for which are still disputed, William Hartnell left Doctor Who, again for reasons that are still disputed. It could be that he was too expensive an actor (he was being paid well over three hundred pounds a week, at a time when that was the price of a new car), he had quarrelled with Lambert’s successor as producer, and was also suffering from the early symptoms of arteriosclerosis, which killed him in 1975. Whatever it was; Hartnell was out, and the younger, fitter, and cheaper Patrick Troughton was in.

One of the first stars of television, Troughton had made a specialism of British folk figures as not only television’s first Robin Hood, but also its first Guy Fawkes. (He had also, like a surprising number of other actors who have also played the Doctor, taken on the role of Winston Smith in an adaptation of 1984.)

The script to Troughton’s landmark first appearance – written by Doctor Who’s first script editor/head writer David Whitaker, who returned to the series for the occasion – is extremely clever, with his character refusing to confirm or deny that he is the Doctor, and occasionally referring to himself in the third person. It’s only when the Daleks recognise the shabby stranger in the ludicrous Paris Beau hat as their nemesis, that the audience and companions Ben and Polly are fully behind the series’ new star.

The “Power of the Daleks” is one of Doctor Who’s‘ “lost stories”; its videotape transmission masters having been erased shortly after transmission – as per BBC practice of the time – and none of the film copies made for foreign sales have ever made their way back to the BBC. (This is the process whereby most monochrome Doctor Who that does exist, exists.) As the first appearance of the first replacement Doctor, this is perhaps the most missed episode of all. We can’t ever really know how Patrick Troughton handled his seemingly impossible task. Fortunately the soundtrack of the episode survives, recorded off air during transmission by an enterprising fan, and in 2016 an animated version of the story was made and released on DVD, synced to that original soundtrack.

While this change of actor, which certainly assured Doctor Who’s longevity, is now thought of as being a radical step, it was a fact that passed much of the series’s then child audience by. My own mother reviewed the first episode in her schoolbook on Monday 7 November, writing, “Dr Who is now Patrick Troughton. I think he is a great actor.”

“Spearhead from Space”

3 - 24 January 1970

A new decade bought a new Doctor and a new format, with the Tardis immobilised and the Doctor unable to leave Earth. The series was also made in colour for the first time. On the face of it, a bold new era, but it was confidently expected by many within the BBC that Doctor Who had run its course and that Jon Pertwee’s first series would also be his, and the programme’s, last. Yet Pertwee’s portrayal proved so popular that he stayed on the programme for five series, two more than either of his predecessors, and by 1972 the programme was once again routinely seen by more than ten million people – sometimes over 12 million – way up from from 1969, when it had fallen to little more than three million.

This opening story was the victim of industrial action concerning BBC studio space, and thus shot on location at BBC training premises and all on film, rather than Doctor Who’s usual film and videotape mix. This temporary inconvenience for those making the programme in the autumn of 1969 has resulted in the story being the only twentieth century Doctor Who serial available in genuine HD in 2018.

“Spearhead” became one of Doctor Who’s perennials, one of the earliest stories released on VHS, and subsequently issues on DVD and Blu-ray. It was repeated in 1971, and then again in 1999, and its plot and imagery exert a strong influence on many a subsequent Doctor’s first story. (Of which more later.)

It's not just in retrospect that this relaunch was considered a success, two days after transmission the Daily Mirror’s critic Matthew Coady declared it the best serial the seven-year-old series had ever done. The new Doctor he said “Was obviously Harley Street… he looks like Danny Kaye while sounding like Boris Karloff – and that’s a mixture for the connoisseur.”

“Robot”

28 December 1974 - 18 January 1975

After years of conspicuous success, both Pertwee and Doctor Who’s producer Barry Letts were moving on. Letts’ final task as producer was to cast Pertwee’s successor, a little known National Theatre actor called Tom Baker, at the time working on a building site, and produce his first story. In the light of more recent Doctor Who, this seems peculiar. The modern equivalent would be Steven Moffatt casting a new Doctor and producing their first story, before handing over to Chris Chibnall for the remainder of their run.

Written by Lett’s script editor and de facto co-showrunner Terrance Dicks, “Robot” is very much in the style of the old team’s final year; the new Doctor is surrounded by the old Doctor’s supporting cast (and uniquely, driving his car) and fighting an earthbound menace with the assistance of the army – the core format of the Pertwee years. Purely for practical reasons (the buildings were owned by the BBC and could be used gratis) much of the story was shot in the same locations that had been used in “Spearhead from Space”. Actor Nicholas Courtney, who played Brigadier Lethbridge-Stewart in both stories, has said that this coincidence seemed rather odd to him, even at the time.

Baker’s performance is so unexpected, so different, and so genuinely remarkable, that even now, after 45 years in which it’s become a touchstone in British popular culture, the story still seems fresh and vibrant – despite him being surrounded both literally and figuratively by the furniture of the previous era. The early Tom Baker years would sustain and build on the successes of the early Seventies, with the series holding onto its ten million plus viewers, and pushing into the top ten programmes of the week.

The effect was pretty much instantaneous; Baker’s sixth episode was the first to be seen by more than 13 million people since 1965. Baker recalls going into his local in then run-down Notting Hill Gate, where he was greeted with “Hello Doctor” and unable to buy his own drinks all night in a pub where, as a jobbing actor, he’d been quietly drinking as recently as the previous week.

“Castrovalva”

4 January - 12 January 1982

Doctors’ first stories essentially fall into two categories. There are those in which, after a brief interval, the Doctor is quickly back to their new/old self, and then there are those that concern themselves with how the Doctor puts themself back together after the regeneration. “Robot”, in which the permanent Tom Baker Doctor is in place after just eleven minutes, is an example of the former. “Castrovalva” is very much the latter. Peter Davison’s Doctor, weakened by trauma, is initially erratic, suffering memory loss and absent-mindedly calling his current companions by the names of characters from the series’s past. He even spends much of the story’s second quarter in a wheelchair and isn’t really wholly together until a few scenes before the end.

There’s a school of thought that says that this shouldn’t really work; Doctor Who is an adventure series dependent on a strong lead and a lot of excitement, but “Castrovalva” squares the circle. Perhaps due to inheriting geometric distortion properties from the work of M C Escher, from which it takes its name, some imagery, and some plot inspirational particularly in its final third. No, really.

Thankfully, Davison’s performance, whether as the confused Doctor of the early stages, or confronting the Master at the serial’s conclusion, is tremendous, and despite being written by the script editor of the final Tom Baker series, the story feels fresh. The wider audience obviously took to it; Davison’s first series averaged roughly double the audience of the final Tom Baker years, frequently hitting that magic ten million figure. Renewal in office is a tricky thing, and Doctor Who was beginning to make it look easier than it was. As those making it were soon to discover.

“The Twin Dilemma”

22nd - 30th March 1984

Davison moved on from Doctor Who quickly, having been advised by Patrick Troughton to only do three series, which were transmitted over a period of a little over two years. His successor Colin Baker’s first turn in the Tardis is an extreme example of the “Doctor putting himself back together” story.

Veteran TV scriptwriter Anthony Steven, who had never worked on Doctor Who before, handed in around an episode and a half’s worth of material for a four-part serial, forcing script editor Eric Saward to extemporise two and a half episodes of his own to complete it, and with little idea of what Steven had intended. The result is an incoherent rush written script about giant slugs, supernovae, and further maths.

Things got worse when industrial action at the BBC meant that the story lost several of its studio days to Peter Davison’s last outing, forcing producer John Nathan-Turner to beg and borrow BBC resources in order to get the serial made at all. It’s churlish, but essentially true, to say that it would have been better for all concerned had he failed.

Baker’s Doctor is so unhinged by the metamorphosis through which he has suffered that he is not merely brusque and abrasive, but briefly homicidally violent, attempting to choke his companion (and audience identification figure) Peri with his bare hands. Baker is superb, giving a detailed and unsettling performance, but creatively the role he’s been asked to play is a horrendous mistake. It’s arguable that this rushed serial set the series off on the wrong course, creating tonal problems that would not resolved for years. It is unavoidably true that it is one of half a dozen Doctor Who serials to lose viewers between every one of its episodes.

“The Twin Dilemma” is often voted by fans as the worst Doctor Who story ever made. This is because it is one of the worst Doctor Who stories ever made.

“Time and the Rani”

5 - 28 September 1987

While 21st century Doctor Who debuts are usually seen as moments of renewal, by this point in the Eighties they were more like desperate throws of the dice. Colin Baker’s contract had not been renewed by BBC management, despite any problems the series was suffering being at best adjacent to his involvement. Nathan-Turner had been instructed to stay with the programme, despite wanting to leave, having been told his only alternative was to resign from the BBC entirely. Perhaps taking a leaf out of Barry Letts’ book, the producer cast a little known National Theatre actor as the Doctor: Sylvester McCoy who, oddly, also shared something else with Tom Baker. Both had, as young men, trained for the priesthood before losing their faith. It was to Patrick Troughton, though, rather than the elder Baker, that Nathan-Turner was looking to in his casting of McCoy: a small man capable of both clowning and melancholy.

McCoy’s first story “Time and the Rani” emphasises the clowning rather than the melancholy, perhaps due to internal BBC complaints that recent series had been too dark and violent. Its production is almost ludicrously contemporary, with a soundtrack that suggests the Pet Shop Boys’ Actually (the album was released the same day the series launched) and a colour scheme that never lets a retrospective viewer forget that this is 1987 as well as outer space. It’s silly and whizzy and camp feels like it belongs on CBBC rather than in prime time. It’s also pretty joyous, in its own way.

Gareth Roberts, a writer for Doctor Who between 2007-2014 and a figure on its most successful spin-off The Sarah Jane Adventures (2006-2011) has described the story as feeling like “someone has opened the windows” to let light and air into a series that had become dusty and morbid, and a necessary stage for the programme to move through in finding itself again.

Back in 1987, however, Doctor Who fans on the whole hated it, which was unfortunate since, with the series scheduled against the then ratings behemoth Coronation Street, they were the only ones watching. Within two years, despite the series having arguably achieved the creative renewal it sought (the Guardian famously called the last Doctor Who story made in 1989 “quintessentially splendid”) and McCoy’s own popularity, the programme was cancelled.

“Doctor Who”

27th May 1996

Nearly seven years after McCoy’s last appearance as the Doctor, he was back. Well, for a few minutes, before handing over to Paul McGann as part of the plot of the only Doctor Who TV story of the Nineties. It was a big budget American co-production, the BBC then believing co-production money and assured US broadcast necessary for a British sci-fi series to succeed. It also doesn’t have another title of its own. The episode, like the series, is just called “Doctor Who”.

Its hospital setting and temporarily incapacitated Doctor pay deliberate homage to “Spearhead from Space”, and this is another Doctor puts himself back together story. Which might be considered a mistake when there was no guarantee there would be a second outing for this version of the programme, it being officially a one-off pending a decision on further investment.

McGann’s Doctor was generally praised, but the best thing in the show is Eric Roberts’ turn as the Master, who glides from earnest to camp to snarling, neck-snapping revenant with the ease of the Oscar nominee he is.

This TV movie, for all the largely justified criticisms of its transatlantic style and absolutely nonsensical plot, did jolly well in a mid-evening slot on the Whitsun bank holiday Monday on BBC One, drawing in nearly ten million viewers, the first time Doctor Who had managed that since 1982. Unfortunately it didn’t do nearly so well for American co-producers Fox, and with both parties needing to be satisfied for there to be any possibility of further adventures, the series went back into hibernation for most of a decade.

“Rose”

17 March 2005

New century, new Doctor. Same show. While bold, new and exciting in all kinds of way – not least in the remarkable casting of Christopher Eccleston and Billie Piper as the title characters of the series and the episode respectively – this is also another story that consciously draws on “Spearhead from Space”, going so far as to borrow its opening shot of the earth from space, ape its orange/red title sequence, feature its monsters, and recreate one of its most famous scenes; as department store mannequins come to life, break through shop windows and start gunning down civilians.

Unlike McCoy in 1996, McGann wasn’t asked back to do a handover scene with his successor when the programme was relaunched in 2005, with showrunner Russell T Davies preferring for his version of Doctor Who to hit the ground running, and boy did it do that. This was one of the ten most watched television programmes of the year .

You can watch the whole thing and every subsequent episode on this list, right now, on iPlayer.

“The Christmas Invasion”

25 December 2005

Six months later, the Eccleston era was over, the actor moving on after one hugely successful series. Davies cast David Tennant, with whom he’d recently worked on BBC Three’s Casanova, to succeed him. Tennant’s first full episode was the centrepiece of BBC One’s Christmas Day schedule, introduced by the station’s announcer as “the Christmas present we’ve all been waiting for”.

No pressure then.

The opening shot is a reference to “Rose”’s own nod to the beginning of “Spearhead from Space”, which also supplies some repurposed dialogue about the human race drawing attention to itself. In echoes of “Robot”, much of the story is built around the old Doctor’s supporting cast – including Rose’s boyfriend and her mother. But it’s back to “Spearhead” again for the way the Doctor is unconscious for most of the story, before emerging fully formed to solve every problem put in front of him with swagger and elan.

Tennant barely features in the first 40 minutes of this 60 minute special. During this time, the audience and the show’s other characters alike were equally sceptical at the idea that he was the Doctor, but it’s fair to say that once he finally appeared, and didn’t stop talking for more than a few seconds at a time, the audience’s love affair with Tennant was instant and total. One of Doctor Who’s imperial phases beckoned, with the series routinely a weekly top ten show, and episodes in 2007, 2008, and 2009 again featuring in the top ten programmes of their respective years.

This was the first ever deliberate Doctor Who Christmas special. There’s been one every year since, with the programme now having been shown on more successive Christmas Days than anything other than the “Big Two” soaps and the Queen’s Christmas Message.

“The Eleventh Hour”

17th April 2010

This is another hit-the-ground-running story. Bar the odd line, and that he is wearing his predecessor’s clothes, the new Doctor is all systems go from the first minute, and Smith’s performance is astonishing right out of the gate.

Russell T Davies had left Doctor Who at the same time as David Tennant, and new showrunner Steven Moffat’s script openly draws on “Rose” and its own antecedents in “Spearhead” (the setting, again, is a hospital) while its climax borrows from “The Christmas Invasion”, with the new Doctor asserting his position as Earth’s defender and making an alien spaceship run away by letting them know who he is.

Lots of people, including many in the BBC, believed modern Doctor Who could not survive, let alone prosper, without David Tennant and Russell T Davies. “The Eleventh Hour” is 60 minutes of television that comprehensively demolishes that contention – seemingly effortlessly. (Smith’s Doctor, would continue the previous series’ success, and rank in the top ten programmes of the year in 2010 and 2013.)

The Eleventh Hour is one of the best Doctor Who stories ever made.

“The Name of the Doctor”

18 May 2013

Look, John Hurt counts, okay? His Doctor, retrospectively introduced as unseen incarnation between McGann and Eccleston, first appeared in a cameo/cliffhanger at the end of this episode before appearing as the co-lead in the fiftieth anniversary special six months later. The onscreen credit “Introducing John Hurt as the Doctor” came as a huge surprise to almost all the audience, and is perhaps the closest the series will ever get to introducing its permanent lead unexpectedly without advance publicity.

One of the many fun things about Hurt’s Doctor is that he appears in three episodes of the series and that they take place, from his character’s perspective, in a completely different order from that which they were presented to the audience.

“Deep Breath”

23 August 2014

Peter Capaldi’s debut is sufficiently consciously modelled on Tom Baker’s that it feels able to quote dialogue from the opening scene of “Robot”. Again, it’s a story in which the new Doctor is surrounded by the old Doctor’s supporting cast, and it takes place in the late Victorian era setting that had dominated Matt Smith’s last series. “Spearhead” exerts an influence again, with the Doctor initially confined to bed before bursting out to take control of the story with his renewed vigour.

“Deep Breath” also nods, daringly, to “The Twin Dilemma”, in its presentation of a caustic and at times seemingly sinister Doctor, although it does not go as far as the earlier story as the Doctor is not explicitly murderous.

At 77 minutes, “Deep Breath” is feature length, the longest Doctor Who episode ever made, barring anniversary specials, and, as directed by Ben Wheatley, a director/producer best known for films like A Field in England, it looks and feels more like a British attempt at a blockbuster film than a television episode. Appropriate then, that it was released, simultaneously to its UK TV transmission, at several UK cinemas, followed by a screening in twelve American cities later that night, before rolling out to 550 US cinemas two days later. The UK screenings alone took half a million pounds, and the TV broadcast was the second most watched programme of the week, one of a handful of times Doctor Who has cracked the weekly top three. The three Capaldi series that followed continued the dourness, even bleak, tone “Deep Breath” at times adopted, perhaps reflecting the national mood of the Britain in which it was made and shown.

“The Woman Who Fell To Earth”

7th October 2018

With a new time slot on a new day, a new showrunner, Chris Chibnall, and new Doctor, Jodie Whittaker, both imported from ITV’s hit Broadchurch, and the promise of adventures for all the family, the success of Doctor Who’s latest reincarnation seems almost assured.