Third Doctor

The Third Doctor was the third incarnation of the Time Lord known as the Doctor.

Regeneration and Exile
When the the Doctor was judged by the Time Lords, after he was caught, following the events with the War Lords and the War Chief, (DW: The War Games) the Doctor was sentenced to a forced regeneration and was exiled on Earth in the 20th century, with his memory blocked so he could not use his TARDIS to escape. He was later found, collapsed outside the TARDIS, and brought to a hospital in a coma, where his unusual anatomy confounded the medical doctors.

Concurrent with the Doctor's arrival, a swarm of power units for a non-physical alien intelligence known as the Nestene Consciousness, mistaken by the Humans as meteorites. Normally disembodied, it had an affinity for plastic, and was able to animate Humanoid facsimiles made from that material, known as Autons. The Nestene Consciousness took over a toy factory in London, and planned to replace key government and public figures with Auton duplicates. In the end, UNIT, with the help of the Doctor and device he constructed, were able to defeat the Autons and the Nestene. The Brigadier feared that the Nestenes may return and asked for the Doctor's help. The Doctor agreed to join UNIT in exchange for facilities to help repair the TARDIS and a car like the sporty antique roadster he had commandeered during the incident. At his insistence, Liz stayed on as his assistant.(DW: Spearhead from Space)

Liz Shaw and incidents on Earth
Summoned by the Brigadier to an underground research centre at Wenley Moor, the Doctor and Liz Shaw met the Silurians, the first time either had met the species. Discovering the truth about the first rulers of the planet Earth, who had gone into hibernation millions of years ago but were revived by power from the research centre. The Doctor strove for peace between reptiles and Humans and even managed to gain the trust of the old Silurian leader. However a rebellious young Silurian seized power and released a deadly virus that threatened to wipe out Humanity.

The Doctor found an antidote with the help of Liz, but the Silurians retaliated by taking over the research centre; preparing to destroy the Van Allen Belt, a natural barrier shielding the Earth from solar radiation harmful to Humans but beneficial to reptiles. The Silurians were tricked into returning to their caves when the Doctor overloaded the reactor, threatening to cause a nuclear explosion. The Brigadier, to the Doctor's disgust, then had the Silurian base blown up. (DW: Doctor Who and the Silurians)

The Doctor then helped radiation-dependent alien ambassadors who had been kidnapped by the xenophobic ex-astronaut General Carrington. Carrington wanted to discredit the aliens and convince the world to wage war against them. The Doctor and UNIT were able to thwart his plans and arrange the safe exchange of ambassadors for astronauts. (DW: The Ambassadors of Death)

Liz's last regular association with the Doctor and UNIT occured when UNIT was providing security cover at an experimental drilling project designed to penetrate the Earth's crust and release a previously untapped source of energy. Soon however the drill head started to leak an oily green liquid that transformed those who touch it into vicious primeval creatures with a craving for heat. The Doctor was accidentally transported by the partially-repaired TARDIS control console into a parallel universe where the drilling project was at a more advanced stage and, opposed by his friends' ruthless parallel selves, he worked to save both universes. While the drilling site in the alternate universe was destroyed, it but gave the Doctor information on the course the project would take, allowing him to save his own universe. (DW: Inferno)

Liz had extensive training, but it  paled in comparison to the Doctor's own knowledge of the universe and scientific principles far beyond that of Earth's. Eventually, she resigned from UNIT and returned to Cambridge. She reportedly told the Brigadier that all the Doctor really needed was "someone to pass him his test tubes and tell him how brilliant he was". This feeling probably contributed to her decision to return to her own research. (DW: Terror of the Autons)

Enter the Master and adventures with Jo
A renegade Time Lord known as the Master arrived at a circus run by a man named Luigi Rossini and stole a dormant Nestene energy unit from a museum. He reactivated it using a radio telescope and used his hypnotic abilities to take control of a small plastics firm run by the Farrel family, where he organised the production of deadly Auton dolls, chairs and daffodils. The Master had a scheme to destroy Humanity and silence the Doctor forever using the Nestene. Aided by the Brigadier and his new companion Jo Grant, the Doctor ended the Master's plans. (DW: Terror of the Autons)

The Doctor and Jo visited Stangmoor Prison for a demonstration of the Keller Machine, a device claimed to be capable of extracting negative emotions from hardened criminals. The Doctor discovered that the Master was behind the machine and the Master lost control of his own machine. Finally, the machine was destroyed, but the Master escaped again. (DW: The Mind of Evil) After the arrival of the Master on Earth, the Time Lords began to allow the Doctor limited use of his TARDIS, but always compelled it to return him to 20th century Earth when his missions were completed, essentially turning him into "some sort of a galactic yo-yo". It began after the Axos invaded Earth, thanks to assistance from the Master. The Axos were defeated and the Doctor started to travel with the Time Lords permit. (DW: The Claws of Axos)

When the Time Lords discovered that the Master had stolen their secret file on the Doomsday Weapon they decided to send the Doctor to retrieve it for them. The Doctor travelled again during his exile and Jo left the planet for the first time. They helped the colonists to stay in the planet but the Master escaped again. (DW: Colony in Space)

The Doctor discovered that in Devil's End, an old evil was asleep and tried to stop his awakening, but the Master, posing as a rural vicar, showed at first to summon the last of the Dæmon's kind, Azal, for his personal gain. Almost in the end, Azal finally decided to give his power to the Master, and fired energy at the Doctor to kill him. However, Jo, stepped in front of the Doctor, asking Azal to kill her instead. This act of self-sacrifice did not make sense to Azal, and the confusion sent him into an agony. He shouted for all of them to leave as he was dying. Bok reverted to his stone form, and as everyone ran out of the church, it blew up. The Master tried to escape in Bessie, but the Doctor's remote control brought the car back, and the Master was taken at last into custody, to be put in maximum security. (DW: The Dæmons) The Doctor found the Daleks again, after a long time thinking that they were dead. Ruling in a near future, freedom fighters from the future tried to attempt to thwart the Dalek invasion by coming back in time to assassinate a delegate at the second World Peace Conference. It was later explained to him that they were attempting to kill Styles because he caused an explosion at the peace conference, starting a series of wars that left Humanity vulnerable to Dalek conquest, a history that they wished to change. The Doctor realised that the explosion was actually caused by Shura in a misguided attempt to fulfil his mission. Returning to the 20th Century with Jo, he had Styles' house evacuated. Daleks and Ogrons arrived in pursuit, but were destroyed when Shura detonated his bomb. (DW: Day of the Daleks) The Doctor and Jo took a test flight in the TARDIS, but arrived on the planet Peladon. Seeking shelter, they entered the citadel of the soon-to-be-crowned King Peladon, where the Doctor was mistaken for a Human dignitary summoned to act as Chairman of a committee assessing an application by the planet to join the Galactic Federation. A great conspiracy was in fact alive between everyone and only the Doctor and Jo were able to help the King. The traitors were eventually killed and the Federation and the Peladon Kingdom returned to normal, the Doctor and Jo leaving. (DW: The Curse of Peladon)

The Doctor and Jo visited the Master, now held in captivity on Fortress Island prison, after being captured by UNIT. (DW: The Daemons) The Master was being held indefinitely and was the only prisoner. He claimed to have reformed but refused to reveal the location of his TARDIS. As they departed, the old-school patriotic governor, Colonel Trenchard, told them that some ships had been mysteriously disappearing. The Doctor could not resist investigating and he and Jo were soon attacked by Sea Devil while examining a Sea Fort. This man-sized bipedal lizard was called a Sea Devil by a crew member who had been driven half mad. The Doctor meanwhile discovered that the Master, assisted by a misguided Trenchard, was stealing electrical equipment from the naval base to build a machine that would control the Sea Devils. The Time Lord intended to use the reptiles as an army to enable him to conquer the planet, and he began by using the machine to summon some of them from the sea. The Doctor entered the Sea Devil's base and tried to encourage peaceful negotiation, recalling how he had failed to broker an agreement between mankind and the Silurians, but matters were left unresolved when the base was attacked by depth charges. The Sea Devils were defeated and the Master escaped once more. (DW: The Sea Devils)

The Doctor was summoned by the Time Lords to deliver a special object to an unknown person and was taken to the 30th century, near the end of the Earth Empire. On the colony world of Solos, something was transforming the Human population, turning them into hideous mutants. The Doctor and Jo found out that that was only the beginning. The Doctor, with the help of Professor Sondergaard, discovered that the Solonians had different stages. Ky eventually went into his metamorphoses, dealing with the Marshall and returning peace to Solos. (DW: The Mutants) The Doctor discovered that the Master, in the guise of Professor Thascalos, had constructed, at the Newton Institute in Wootton, a device known as TOMTIT - Transmission Of Matter Through Interstitial Time - with which to gain control over Kronos, a creature from outside time. The creature was summoned but the effect proved uncontrollable. Atlantis was destroyed by Kronos and the Doctor discovered that Kronos wasn't so irrational as it could have been. The Doctor let the Master escape eternal punishment. (DW: The Time Monster)

Freedom and Jo's departure
A superluminal signal was sent to Earth, carrying with it an unusual energy blob that seemed intent on capturing the Doctor. In the meantime, the homeworld of the Time Lords came under siege, with all the power sustaining it being drained through a black hole. Trapped and desperate, the Time Lords broke the First Law of Time, allowing the Doctor to aid himself by summoning his two previous incarnations from the past. Unfortunately, the first incarnation was trapped in a time eddy, unable to fully materialize, and could only communicate via the scanner. The first incarnation deduced that the black hole was a bridge between universes, and the other two incarnations allowed the TARDIS to be swallowed up by the energy creature, which transported them, Doctor Tyler, Jo Grant, Sergeant Benton and Brigadier Lethbridge-Stewart into antimatter universe created by the legendary Time Lord, Omega. The exile away from the universe had made Omega quite insane. Along with his revenge, he had summoned the Doctor's incarnations there to take over the mental maintenance of the antimatter universe so he could escape. However, the Doctor's incarnations discovered that years of exposure to the corrosive effects of the black hole's singularity had destroyed Omega's physical body and he was trapped forever. Driven over the edge by this discovery, Omega demanded that the Doctor's incarnations share his exile. The Doctor's incarnations escape briefly, and offered Omega a proposition. They would give him his freedom if they could send the others back to the positive matter universe. Omega agreed, and when that was done, the Doctor's incarnations offered Omega a force field generator containing the second incarnation's recorder, which had fallen in it prior to the transport through the black hole. Omega knocked the generator over in a rage and the unconverted positive matter recorder fell out of the force field. When the recorder came into contact with the antimatter universe, it annihilated everything in a flash, returning the Doctor's incarnations in the TARDIS to the positive matter universe. The third incarnation explained that death was the only freedom anyone could offer Omega.

With the power now restored to the Time Lords, they were able to send the first and second incarnations back to their respective time periods. As a reward, the Time Lords give the third incarnation a new dematerialization circuit for the TARDIS and restore his knowledge of how to travel through space and time, lifting his exile. (DW: The Three Doctors) The Doctor and Jo arrive the SS Bernice, a cargo ship crossing the Indian Ocean. But things were not as they seemed. A monster appeared in the sea, events repeated themselves, and a giant hand stole the TARDIS. Investigation revealed that they were in fact inside a Miniscope, an alien peepshow sporting numerous miniaturised environments, which showman Vorg and his assistant Shirna had brought to amuse the populace of the planet Inter Minor. After leaving the Miniscope, the Doctor returned all the creatures home and destroyed the machine to never be used again. (DW: Carnival of Monsters) Upon arriving on an Earth freighter the Doctor and Jo became caught up in the escalating tension between planets Earth and Draconia, and discovered that the Master was secretly working to provoke the two sides into all-out war, under the orders of the Daleks. The Doctor, barely conscious due to a shot grazing his head, asked Jo to help him into the TARDIS. He staggered over to the console, dematerialising the ship, then pressed his palms to the telepathic circuits, sending a message to the Time Lords. (DW: Frontier in Space) Injured after a shoot-out between his old nemesis the Master and the Ogrons, slaves to the Daleks, the Doctor sent a message to the Time Lords, asking them to pilot his TARDIS and follow the Daleks to their new base. After he slipped into a coma, it fell to his assistant, Jo Grant, to explore the planet where the TARDIS finally materialised. The Doctor and Jo Grant teamed up with a guerrilla group of Thals on the planet Spiridon, seeking to stop the Daleks from gaining the invisibility powers of the native Humanoid species. They discovered the base with more than 10000 Daleks hibernating and decided what must be done for the sake of the universe. Finally, the Daleks were buried in earth and the Thals thanked the Doctor, leaving the planet on the Supreme Dalek ship. The Supreme didn't give in, saying that the Daleks would return. (DW: Planet of the Daleks) After several attempts to get to Metebelis III the Doctor succeeded in landing his TARDIS there, though he was attacked by several violent beings including a large bird. While on the planet however, he took a blue crystal. Returning to Earth he joined the Brigadier and Jo at a South Wales town of Llanfairfach where UNIT was investigating a miner who had been found in an abandoned coal pit; he was glowing green. Global Chemicals were responsible due to responding to BOSS, the perfect machine designed to learn and give orders, even if it must be by sacrificing persons for the mission. The Doctor succeeded in defeating BOSS. Jo and Cliff Jones, a scientist who was working at a scientific community Wholeweal, announced they were getting engaged and planned to travel the Amazon looking for a rare fungus. The Doctor offered his blessing and gave Jo the blue crystal he had retrieved from Metebelis III as a present, but was evidently very upset by the situation and quietly slipped away while the party was in full swing. (DW: The Green Death)

Adventures with Sarah Jane
Journalist Sarah Jane Smith impersonated her aunt, virologist Lavinia Smith, in order to gain access to a research centre where top scientists were being held in protective custody while UNIT investigated the disappearance of a number of their colleagues. The missing scientists had been kidnapped by a Sontaran, Linx, and taken back to medieval England, where they were working under hypnosis to repair his crashed spaceship. The Doctor and Sarah, following the death of Linx and the destruction of the future weapons, returned together. (DW: The Time Warrior) The Doctor and Sarah arrived in 1970s London to find that it had been evacuated, due to the mysterious appearance of dinosaurs. It turned out that the dinosaurs were being brought to London via a time machine in order to further a plan to revert London to a pre-technological level. Eventually, Whitaker and Grover were transported to their "golden age" and Sarah officially became the Doctor's companion. (DW: Invasion of the Dinosaurs)

The TARDIS crash-landed due to power blackout on the planet Exxilon, upon arriving the Doctor encounter Space Marines who were seeking Parrinium a cure to a space-plague. The Daleks also landed on Exxilon seeking the Parrinium. Both the Doctor and the Daleks discovered the Great City of the Exxilons a large city that had a power-disrupting tower preventing any technology from functioning on the planet. Journeying within the City the Doctor sought to disrupt the city's functions and remove the power-disrupting facility. Concurrently the Daleks ordered humans to place bombs around the City's central tower to destroy it. The City was destroyed along with the Dalek space ship, and the Doctor sadly commented that the universe was now down to 699 Wonders. (DW: Death to the Daleks)

The Doctor returned to Peladon fifty years after his last visit, finding Queen Thalira, daughter of the late King Peladon, on the throne. A tense labor dispute between Pel nobility and miners was worsened when apparitions of their deity Aggedor attacked and killed several miners. The Galactic Federation desperately needed Trisilicate for its war against Galaxy 5, and sent in brutal Ice Warrior troopers to ensure production. The Doctor discovered a devious plot at the heart of Aggedor's appearances. The Ice Warriors revealed to be the causers of everything due to returning to their origins. After they were defeated, Peladon kingdom finally rested in peace and Sarah and the Doctor left without anyone noticing. (DW: The Monster of Peladon)

Guilt, Redemption and Regeneration
The Doctor continued to assist UNIT, though his presence on Earth was now much more intermittent. Mysterious goings-on at a meditation retreat run by Tibetan monks are linked to the blue planet Metebelis III, and a colony of monstrous, evolved spiders. The Doctor must reflect on his past and reconcile with his present to defeat a deadly and possibly fatal challenge... Finally, to defeat the Spiders of Metebelis III, the Doctor sacrificed his own life by exposing himself to lethal levels of radiation. With the assistance of his old mentor K'anpo Rimpoche, he was able to regenerate into his fourth incarnation. (DW: Planet of the Spiders)

After Regeneration
The fourth incarnation seemed to dislike his predecessor. He commented that his new nose was a definite improvement only hours after his regeneration. (DW: Robot) When on Karn, the fourth incarnation mentioned that he preferred his then-current form than "what he had last time". (DW: The Brain of Morbius)

Directly after his regeneration, the eleventh incarnation performed a quick check of his body. When commenting on his nose, he said, "I've had worse", possibly referencing the third incarnation. (DW: The End of Time)
 * For a list of Third Doctor stories in the order in which he experienced them, see Third Doctor - Timeline.

Appearance
Known for his ornate fashion sense, most famously his frilled shirt, smoking velvet jackets and inverness cape outfit. As such, his first and second incarnations called him a dandy.

His was the first incarnation to steal clothes from a hospital, followed by his eighth and eleventh incarnations. (DW: Doctor Who, The Eleventh Hour)

Personality
The third incarnation often had problems with the Brigadier's tendency to think of situations in military terms, and with petty officials, generally. The third incarnation had a continuing series of contests and challenges with the Master, and was the first known incarnation to encounter the Silurians and Sea Devils as well as the Ogrons, and the Autons. (DW: Doctor Who and the Silurians, The Sea Devils, Spearhead from Space, Terror of the Autons and Day of the Daleks) The third incarnation never faced the Cybermen, though he and Sarah Jane Smith did witness a Raston Warrior Robot massacre a squad of Cybermen. (DW: The Five Doctors)

Despite his conflict with the Master, he visited him in prison; Jo noticed that he worried about him; he told her that he was an old friend. (DW: The Sea Devils) He attempted to achieve peace between the humanity and the Silurians; he again tried to come to an agreement with the Sea Devils, he killed them when he saw no other hope. (DW: Doctor Who and the Silurians, The Sea Devils)

His time with UNIT had a lasting effect. Even though his following incarnations pretty much severed all ties with UNIT, the ninth and tenth incarnations worked with them a few times when the need arose. None of the Doctor's later incarnations are known to have resigned this one's position. It was shown that the Doctor was well known within UNIT even up to the late 2000s with all of the members wanting to meet him. Captain Erisa Magambo and Professor Malcolm Taylor were both excited to hear from him with Magambo even saluting him despite it annoying the Doctor. The two described the Doctor as the man everyone in UNIT wanted to meet but feared the day they would as they knew that that day would bring chaos. Magambo also had a habit of saluting the Tenth Doctor out of respect for the acomplishments of the Doctor as a whole, something that annoyed him greatly. (DW: Planet of the Dead) The third incarnation was a man of action, aggressively joining the fray whenever he could, unlike the first two incarnations who generally insinuated themselves into events discreetly. This incarnation was unafraid to pitch in with his physical skills, often bringing his mastery of Venusian aikido into play when the situation called for it.

Much like his predecessors, his keen mind was still his primary asset, and this was an incarnation who particularly loved to create and play with gadgets of all sorts. This passion displayed itself both in terms of the third incarnation's scientific bent and in his love of vehicles, such as his yellow roadster, Bessie, and his car which he specially built.

Staunchly moral, he was every bit the gentleman, a hero of the Victorian mold.

The Doctor had a noticeably antagonistic relationship with his second incarnation. Their relationship was so rocky that they were incapable of working together without the authoritative presence of the first incarnation. (DW: The Three Doctors, DW: The Five Doctors) The nature of the second incarnation's regeneration into the third's may be the cause of their open disliking of each other. By contrast, the fourth incarnation, although he never met himself in his previous incarnation, occasionally spoke rather fondly of that form.

His knowledge of the TARDIS greatly increased in this incarnation (chiefly due to practically taking it completely apart and reassembling it in an attempt to make it work); Once the Time Lords returned the knowledge of how to operate it, the Doctor became far adept at controlling his destinations then his previous incarnations, who often lacked any sort of control at all.

Habits and Quirks
The third incarnation was known for his great passion for gadgets, his love of his vintage car, Bessie, and later, his specially designed futuristic car, almost as much as he loved his TARDIS. (DW: Doctor Who and the Silurians, Invasion of the Dinosaurs)

He would occasionally perform magic tricks. The third incarnation could at times by very tetchy and argumentative, an attitude that he demonstrated repeatedly with bureaucrats and other authority figures. Having been a man of action, he used a wide variety of martial arts including Venusian aikido. He particularly enjoyed wine. (DW: Day of the Daleks)

Mysteries and Discrepancies

 * The newly regenerated Doctor sported a tattoo on one arm. (DW: Spearhead from Space)
 * This was the mark made by the Time Lords to signify the Doctor was an exile. (NA: Christmas on a Rational Planet)
 * Jon Pertwee was once in the navy. It was a sort of tradition to get a tattoo which is why he had one.


 * The Doctor described himself as thousands of years old (DW: Doctor Who and the Silurians), which seems inconsistent with figures of his age given in later incarnations. He repeats that age later to Jo Grant. Previous incarnations of the Doctor gave his age to "some hundred years".
 * See separate article.

Unrecorded Adventures

 * Though sidetracked to the planet Nooma (MA: Speed of Flight), the Doctor, Jo and Mike Yates visited the planet Karfel and encountered the Borad and Katz's father there. (DW: Timelash)
 * In Castrovalva, the fifth incarnation mentions being with the Brigadier and him chasing Ice Warriors, which must have been an unrecorded adventure for him.
 * As the Fifth Doctor was going through a rather unstable regeneration at that point however, the claim of having had an adventure with the Brigadier and chasing the Ice Warriors may not be entirely factual.

Key life events

 * Newly regenerated, partially amnesiac and exiled on Earth, the Doctor re-unites with UNIT and the Brigadier and encounters the Autons and Nestene Consciousness for the first time. Afterwards, having nowhere else to go, the Doctor reluctantly accepts the position of UNIT's unpaid scientific advisor. He is given his own automobile, which he dubs "Bessie", and Dr. Liz Shaw becomes his assistant. (DW: Spearhead from Space)
 * Witnesses the brief destruction of the Silurians and his disgust with UNIT. (DW: Doctor Who and the Silurians)
 * Is briefly sent to a parallel Earth. (DW: Inferno)
 * The Doctor meets Sergeant, later Captain, Mike Yates. (MA: The Eye of the Giant)
 * Liz Shaw leaves UNIT after a second meeting with the Silurians. (MA: The Scales of Injustice)
 * Jo Grant becomes the Doctor's new companion. (DW: Terror of the Autons)
 * A Time Lord warns the Doctor that a former friend turned enemy, the Master, has come to Earth. (DW: Terror of the Autons)
 * Encounters the Daleks for the first time in many years. Also, due to a TARDIS malfunction, accidentally meets a future version of his same incarnation. (DW: Day of the Daleks)
 * The Doctor travels to the planet Peladon and re-meets the Ice Warriors and meets King Peladon and Alpha Centauri for the first time. (DW: The Curse of Peladon)
 * The Master escapes his imprisonment during the Doctor's first meeting with the Sea Devils. (DW: The Sea Devils)
 * With his first and second incarnations, the Doctor defeats Omega. As a reward for this, the Time Lords rescind his exile and restore his knowledge of the TARDIS. (DW: The Three Doctors)
 * With his freedom restored the Doctor begins scaling back his involvement with UNIT and starts travelling through time and space again. (DW: Carnival of Monsters)
 * The Doctor emotionally says goodbye to Jo Grant, who leaves in order to marry Clifford Jones. (DW: The Green Death)
 * The Doctor travels to the planet Peladon and re-meets the Ice Warriors and meets King Peladon and Alpha Centauri for the second time. (CC: The Prisoner of Peladon)
 * The Doctor meets Sarah Jane Smith for the first time. (DW: The Time Warrior)
 * In a timeline created by Faction Paradox, the Doctor dies on the planet Dust. (EDA: Interference - Book One, Interference - Book Two)
 * The Doctor travels to the planet Peladon and re-meets the Ice Warriors and meets Alpha Centauri for the third time. (DW: The Monster of Peladon)
 * The Doctor re-unites with K'anpo Rimpoche, a spiritual teacher and Time Lord, whom the Doctor had known during his youth on Gallifrey. He would help the Doctor regenerate after a confrontation with the Great One. (DW: Planet of the Spiders)

Behind the scenes

 * It is interesting to note that, during his exile on Earth, Torchwood made no known attempts to capture the Doctor, despite him being named in the Torchwood Charter.
 * This could be explained by the fact that Captain Jack Harkness most likely would have stopped them from interfering with his personal timeline. Also, because of the constant changing nature of time, and it being in flux, Torchwood may not have existed. A final possibility is they simply didn't recognize him as the TARDIS was hidden within UNIT HQ and he didn't resemble the incarnation of the Doctor that Queen Victoria had met, and none of Torchwood One displayed any knowledge of regeneration.


 * Due to the absence of the TARDIS as a travel device, for much of the first through third years of the third incarnation's period, this is one of the few known extended periods in the Doctor's life where time passes at approximately the same rate for him as it does for the rest of the universe. Being exiled to Earth, his few TARDIS travels during this time consistently involved his immediate return to the same time on Earth that he left. Using the Humans around him as a measure, the Doctor presumably aged only a few years between the events of Spearhead from Space to The Three Doctors, the point where his exile is lifted and he can time travel freely.
 * "Reverse the polarity of the neutron flow" is thought to be his most commonly used quote, but in fact he only says it fully once.
 * In The Paradise of Death, he admits to Brigadier Lethbridge-Stewart that the phrase doesn't actually mean anything from a scientific point of view.

Casting

 * Ron Moody was approached by the producers after his success in "Oliver" but he turned down the role. He has stated in interviews that turning down the role of the Third Doctor was the worst thing he ever did professionally; every time he hears the familiar Doctor Who theme tune he kicks himself.