The Regeneration of Dr Who

by JoHarrington

As long as he can keep regenerating, the Doctor can now live forever. But for much of his 50 years on our screens, he wasn't that immortal.

For years, Whovians watched the countdown happening. Back in the days when Tom Baker flew through time and space, it was revealed that Dr Who could only regenerate twelve times. Matt Smith was the eleventh doctor (and the tenth regeneration).

That throwaway fact stamped a use by date upon the whole series. Smith's Doctor could die, but whoever replaced him would be the second last. It was an unhappy state for all concerned. Fans and production crew alike could see the sand slipping through the hourglass.

Until the BBC slipped a fast one into a spin-off series. Suddenly there were endless regenerations, and the Doctor was immortal.

Regeneration Poster of the Eleven Doctors

Regenerating the Doctor

As the ninth Doctor sucked the vortex energy from Rose's mind and body, he knew that he would die.  Yet the little smirk betrayed no fear.  "Timelords have this little trick." He blithely told his companion. "It's kind of a way of cheating death."

Rose may have been stunned by proceedings, but the viewers watching at home were not. We'd seen it nearly a dozen times before.

The actual mode of regeneration changed with the advancing special effects, but we knew what the Doctor knew. He was about to transform every cell in his body, and emerge in a totally different body.

This was the trick of the Timelords of Gallifrey.  Not peculiar to the Doctor alone, we'd seen it happen with the Master, Romana and River Song too. 

At a moment of mortal danger, a process would begin, which could not be stopped. The old, dying body would disintegrate into the ether, while the new would form without the injuries, poison, age or whatever other ailments had killed the former.

There were variations on a theme. The second Doctor was forced into his regeneration. His whole body appeared to spin in space. The fourth Doctor seemed to know and welcome his Fate. He beckoned for the assistance of a mysterious figure called The Watcher, who apparently delivered the Timelord's next form. It was all very calm and sedate. The tenth Doctor raged against the coming of the night. He didn't want to go and his regeneration was so explosive that it set the TARDIS alight.

Fans of the show would be treated to the spectacle of a new actor, prancing around in the familiar costume of the last.  The hapless companions would each have to discover the 'little trick' for themselves.

Figurines of Post Regeneration Dr Who

Peter Davison briefly wore the outfit made famous by Tom Baker.
And Colin Baker arrived wearing the costume of Peter Davison

All of the Doctor's Regenerations 1963-Today

The Rules of Timelord Regeneration

After 50 years of witnessing Dr Who metamorphose into somebody new, certain laws of Timelord biology became apparent.

  • Regeneration is a natural occurrence, and is alternatively called 'renewal'.
  • The Doctor's changes are fixed in time and space, therefore destined. How else would K'anpo Rimpoche or the Watcher be able to hang around for the 3rd and 4th Doctors respectively? Or the tenth Doctor know to visit every one of his companions to say goodbye?
  • Though the Doctor keeps his memories (give or take the amnesia of the eighth Doctor), all else is transformed down to a cellular level. This includes his personality.
  • Even while dying, sheer will can keep at regeneration at bay, however temporarily. The fifth Doctor does this in order to save one more life. However this is fraught with danger. The same Doctor worried that he'd held off so long that he wouldn't be able to change.
  • Regeneration can also be postponed by synthetic means. The seventh Doctor couldn't transform until a general anesthetic had worn off.
  • Timelords may only (naturally) regenerate twelve times, as revealed by the fourth Doctor in Deadly Assassin. However, the rulers on Gallifrey may award an extra thirteen life-time cycles, transferring regeneration credits like the denizens of New Greenwich gave time. This gift was awarded to The Master in The Five Doctors.
  • New bodies can also be stolen, as evidenced by the Master twice.
  • Time Lords may, or may not, be able to choose their new bodies at will.  The Rani went through a series of changes, mid-regeneration, before settling on one; while The Master stated his intent to become young and strong, before renewing his body just so.

9th to 10th Doctors Regeneration Action Figures

Doctor Who Regeneration Sticker Guide (Dr Who)

This is a Sticker Guide to the second series of "Doctor Who", starring David Tenant and Billie Piper.

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Doctor Who: Eleventh Doctor Regeneration Sticker Guide (Dr Who)

There's a new doctor in the Tardis! Use the 100 stickers to complete this new "Doctor Who" guide and find out all about the regeneration of David Tennant's "Doctor" into "11th D...

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10th to 11th Doctors Regeneration Fridge Magnet

All of the Master's Regenerations 1963-2010

What Can Kill Dr Who?

It's not so much regeneration, as conscious reincarnation. He comes back fully formed, with all of his memories intact.

So far, the Doctor is not immortal.  The changes come, but they are tempered by their limited number.  He's more like the proverbial cat with nine lives rather than truly living forever.

As for the things which kill him, they are pretty much what might kill human beings too.  Though granted, we don't tend to find ourselves in most of these situations.

  • The First Doctor (William Hartnell) died of debilitation in old age.  He'd been fighting Cyberman in the Antarctic, when the strain grew too much.  He collapsed in the TARDIS. His horrified companions, Ben and Polly, witnessed his renewal.
  • The Second Doctor (Patrick Troughton) had no choice in his regeneration. He stood accused of interference in a court assembled by his fellow Time Lords.  His punishment was to be exiled to Earth, without any knowledge of his TARDIS. His companions, Jamie and Zoe, were returned to their own point of origin, similarly stripped of their memories of The Doctor. By the time the 2nd Doctor crash-landed onto Earth, the trauma was enough to force his body to change.
  • The Third Doctor (Jon Pertwee) was fatally exposed to radiation from crystals, while facing down giant spiders on the planet of Metebelis III.  Sarah Jane and the Brigadier were there as he died, then stood shocked by the sudden appearance of K'anpo Rimpoche. The genie-like avatar was also a Time Lord and the Doctor's old mentor. K'anpo intervened to trigger the Doctor's regeneration.
  • The Fourth Doctor (Tom Baker) fell from an upturned radio dish, which the Master was rotating in a successful attempt to dislodge him. As Nyssa, Tegan and Adric raced to the Doctor's side, the shrouded figure of the Watcher was spotted waiting by.  Though suffering multiple injuries, the broken Doctor summoned the strength to wave the Watcher closer. It stepped into him and the regeneration process occurred.
  • The Fifth Doctor (Peter Davison) was gassed to death on the planet Androzani Minor. He had the antidote to the deadly toxin Spectrox, but only one dose.  His companion Peri was also dying, so the Doctor heroically staved off his own regeneration. He carried her to the TARDIS and gave her the antidote, before collapsing himself.  He'd previously worried that he wouldn't be able to renew himself, as he'd waited too long while dying. The terrified Peri cowered in horror, as the Doctor transformed anyway.

Collector Set of all 11 Doctor Who Action Figures

  • The Sixth Doctor (Colin Baker) was fatally injured/forced into a regeneration during an attack on the TARDIS by a Time Lord named The Rani.  It was never actually explained on-screen what triggered it.  All viewers (and companion Mel) saw was the Doctor prone on the floor of the TARDIS. Unconscious, he was turned onto his back and revealed as having regenerated.  It's a plot hole beloved of Whovian fan fiction writers.
  • The Seventh Doctor (Sylvester McCoy) was shot by gangsters in San Francisco. This shouldn't have been fatal, but medics at the local hospital had no idea they were operating on an alien. Surgeons heard the dual beating of two hearts and assumed it was a single one in need of fibrillation. The shock killed him. However, anesthesia delayed the onset of his regeneration. He later changed, all alone, in the hospital morgue.
  • The Eighth Doctor (Paul McGann) crash-landed on the Planet Karn. He was offered the choice to control his regeneration with a draft prepared by the Sisterhood of Karn. Furious with the state of the war between Time Lords and the Daleks, he chose to become the Warrior.
  • The Warrior (John Hurt) will be shown in the 50th Anniversary Special.
  • The Tenth AND Eleventh Doctor (Christopher Eccleston) effectively commits suicide with a kiss.  His beloved companion Rose has looked into the heart of the TARDIS, thus absorbing into herself time vortex energy.  It's all too much for her fragile human form to withstand, so the Doctor draws it into himself.  Nor could he safely absorb it, but at least he could regenerate, while Rose looked tearfully on.
  • The Twelfth Doctor (David Tennant) is poisoned by radiation, while rescuing Wilfred Mott from the Gate to a Time Lock.  His death is perhaps the most poignant of all the regenerations thus far, because of its longevity and the fact that this Doctor didn't want to die.  He spends hours secretly visiting all of his past companions or their descendants, though he doesn't reveal himself to all. Ultimately he dies alone on the TARDIS; while out in the universe, the Ood sing to his passing, 'This song is ending, but the story never ends.'
  • The Thirteenth Doctor (Matt Smith) died of old age and being shot at by Daleks. Tellingly, it was the first item which was the pertinent point. We can't have the Doctor dying to a mere Dalek!

Peter Capaldi starts a whole new regeneration cycle of thirteen lives, which technically makes him the Second First Doctor.  But that's going to be way too confusing.  The likelihood is that we'll all forget that The Warrior was the Ninth, and pin that accolade back onto Christopher Eccleston. Then ignore too his double regeneration, to make David the tenth and Matt the eleventh.

Peter will sail into the Whovian hive-mind as the twelfth Doctor. Even if he is the Second First.

Nevertheless, he's still with us and therefore not included in this round up.


Limited Edition Dr Who Regeneration Watch

Doctor Who Lenticular Regeneration Watch - Limited Edition

Collectible regeneration watch for any Doctor Who fan. A worldwide limited (and individually numbered) edition of just 2,500 pieces

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Sarah Jane Adventures: Dr Who Can Change 507 Times

Dr Who Declares Himself Immortal Now

It used to be that he could only regenerate twelve times. Now it appears that it's many more than that.

Was it sarcasm?  A throw-away line designed to impress a teenager?  Whatever his motives, the Eleventh Doctor ran contrary to all previously established facts, when he informed Clyde that there were 507 regenerations in him.

In truth, Whovians had been expecting it.  After all, the BBC were not going to let such a lucrative franchise die, just because none of their Doctors could apparently survive longer than eight years in a single form.  Something was going to have to change. Whole forum threads and conference debates were staged to speculate on how Time Lord lore would be changed.

The reality was a bit of an anti-climax.  It didn't even occur in a Dr Who story, but in a spin-off - The Sarah Jane Adventures.  From 12 to 507 wasn't a bad difference.  It would take a lot of regenerations before they were all worked through. But was it a cop-out?

Director Russell T Davies stated that it was just too good an opportunity to miss. Fans just face-palmed. Many refused to even consider it canon, as it hadn't been stated in the main show. Everyone wanted it, but not like this.  There had to be some great story device to change things, not the laws of Time Lord biology simply being erased with a word.

However, it all transpired to be a joke. The Doctor did only have thirteen regenerations in him, unless Gallifrey saw fit to award him another cycle.  And guess what they did!  Who would have thought it?

The Eleventh Doctor Regenerates into the Twelfth!

By which we all mean that the thirteenth Doctor became the Second First. Ok! I give up! Matt was the 11th and Peter is the 12th. Play on!
Updated: 07/22/2014, JoHarrington
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JoHarrington on 07/18/2013

Matt's doctor seems to be with Sylvester McCoy to my mind. I do love him, I just prefer the darker doctors, like Tennant. Which probably says a lot more about me than them!

I'll ask Chef Keem to help with your password. <3

Ianjames on 07/18/2013

Great article, though I am shocked, apalled and dismayed that you don't rate Matt's doctor. As seems to be the cliche for fans now, I'm going to say he copes well with difficult scripts (though personally I think Tennant's doctor coped poorly with difficult scripts). Some great memories of being an obsessive fan as a child here.
Think I might come back to Wizzley, if I can rmember my log in.

JoHarrington on 05/02/2013

Matt Smith is a little too slapstick for me, but he does have his moments too. Like that speech a couple of episodes back. I agree that he is of an ilk with Sylvester McCoy. I recently read something which said that McCoy's Doctor was very dark. I didn't agree with that at all. I thought he did 'zany', which is precisely what Matt Smith does too.

The best Dr for me is David Tennant, though 'my' doctor is Peter Davison. Best companion is a little harder. I have fond memories of Tegan, Adric and Nyssa, because that's really where I came in (though I've since seen the earlier ones too). Donna Noble was fabulous.

I hadn't thought about the whole sonic screwdriver thing. You are right.

JoHarrington on 05/01/2013

Indeed! I recall a whole conversation with yourself and Warlock about Dr Who. Though I suppose that I was letting you both do most of the talking. Definitely a big fan here.

Ah! I hope that you're right about the explanation. Maybe the quip in the Sarah-Jane Adventures was just that. Something with which to sound out the fans, then dismiss or elaborate upon later.

Cossack on 05/01/2013

Great article again! I didnt realise, or forgot, that you were as much of a Dr.Who fan as me, and that you also wish David Tennant had stayed :) I am excited to see what they come up with for the whole unlimited regeneration thing, since everyone is going on about it i'm pretty sure they won't leave it as it is. The teenager-mpressing thing was probably just to make people wonder and anticipate the actual explanation more. -Coss

JoHarrington on 04/27/2013

I watched them too! But only live from Tom Baker onwards. The rest I had to see on video tapes. Can you imagine what media people will be watching on, if it did get to 507?!

SquidRich on 04/27/2013

The scary thing is I watched all of these regenerations as each occurred and wonderful to see them again. Hopefully, the good Doctor has some more in him (507?)

JoHarrington on 04/25/2013

Thank you very much on both counts, Paul. I'm off to read your Dr Who Episodes article now, while looking forward to those which you'll be posting here too.

pkmcr on 04/25/2013

Oh! Have just shared on G+ and also on my page at

pkmcr on 04/25/2013

I will be adding some more over the coming weeks :-) Here's the link to the page with all the "must watch" episodes and of course a chance to share who "Your" Doctor is!

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