The Third Doctor (1970-1974)
Season Seven 
(1970) Season Seven (1970): Exiled To Earth
First appearances of Liz, the Autons and the Silurians. The Doctor becomes UNIT's scientific adviser. Doctor Who is broadcast in colour for the first time.

Season Ten (1972-73): A Return To Wandering
First multi-Doctor story. The Doctor's exile is lifted.
Season Ten 
(1972-73)
Season Eight 
(1971) Season Eight (1971): Enter -- The Master
First appearances of Jo, Yates and the Master.
Season Eleven (1973-74): Facing Fears
First appearances of Sarah Jane and the Sontarans. The Doctor's home planet is named as Gallifrey for the first time.
Season Eleven 
(1973-74)
Season Nine 
(1972) Season Nine (1972): A Galactic Yo-Yo
First appearance of the Sea Devils.

Season Seven (1970): Exiled To Earth

The Doctor
The Third Doctor

Jon Pertwee (bio) played the Doctor from Spearhead From Space in January 1970 to Planet Of The Spiders in June 1974.

Companions and Recurring Characters

Liz Shaw was a brilliant scientist who served as an advisor to UNIT.

Caroline John (bio) played Liz from Spearhead From Space in January 1970 to Inferno in June 1970.

Liz Shaw

The Production Team

Early in the season, Peter Bryant and Derrick Sherwin were both abruptly moved to another programme. Appointed to replace them was Barry Letts (bio), who had previously directed The Enemy Of The World for the series. Together, he and Terrance Dicks became one of the longest-lasting production teams in Doctor Who's history, remaining intact throughout the Pertwee era.

The Stories
Spearhead 
From Space
Spearhead From Space by Robert Holmes, directed by Derek Martinus
The newly-regenerated Doctor is exiled to modern-day Earth by the Time Lords, where he becomes attached to the British branch of UNIT as their scientific adviser, ostensibly taking orders from Brigadier Lethbridge-Stewart. The Doctor's first task is to investigate a shower of strange plastic meteorites which landed in the countryside. Nearby, a dollmaker named Ransome discovers that his plastics factory has been taken over by a mysterious man called Channing. Now its corridors are stalked by deadly animated mannequins called Autons, who are determined to recover the last of the meteorites.
Cambridge scientist Liz Shaw joins UNIT as the Doctor's assistant.
The 
Silurians
The Silurians by Malcolm Hulke, directed by Timothy Combe
UNIT is called to a nuclear reactor on Wenley Moor, which has been plagued by strange power disruptions and a wave of nervous breakdowns. The Doctor suspects a connection with a nearby network of caves, and is stunned to find a dinosaur hunting in the tunnels. He discovers that the reactor has inadvertently awakened the Earth's original inhabitants: the reptilian Silurians, who have lain underground in suspended animation for millions of years. Now the Doctor must determine whether there is any possibility for peace between the two races -- or whether a catastrophic conflict is inevitable. (Also known as Doctor Who and The Silurians. This story has been recolourised, as the original prints are missing.)
The 
Ambassadors Of Death
The Ambassadors Of Death by David Whitaker, directed by Michael Ferguson
A manned mission to the Red Planet, Mars Probe 7, is returning to Earth, but there has been no communication from the astronauts for several months. Recovery 7 meets it in orbit, but then the signal is suddenly cut off by an alien noise. When the recovery capsule touches down, UNIT is ambushed and the occupants vanish. However, the Doctor and Liz discover that the capsule interior is highly radioactive: whatever came down in Recovery 7 couldn't possibly have been human. As the Doctor searches for the missing astronauts, he begins to realise that he is up against a vast conspiracy reaching into outer space. (Episode one is retained in its original colour, while episodes two to seven have been recolourised, as the original prints are missing.)
Inferno
Inferno by Don Houghton, directed by Douglas Camfield
Project Inferno is designed to drill down through the Earth's core, where it will release a powerful new energy source called Stahlman's Gas, named after the project's director. But the Doctor realises that unleashing Stahlman's Gas will have horrible consequences for the planet, and indeed his fears are confirmed when a substance oozing up from the drill shaft begins mutating men into bestial monsters. Before the Doctor can do anything to stop Stahlman, however, a power surge in the TARDIS console sends him to a hostile parallel universe where Project Inferno is nearing completion.

Making History

The changes envisaged over the course of the previous year came to fruition with Season Seven: Doctor Who was now in colour, with a new Doctor exiled to modern-day Earth, working alongside Brigadier Lethbridge-Stewart and UNIT. The revamped format lent itself to new producer Barry Letts' vision of the Doctor Who target audience as consisting of teenagers and even adults, rather than younger viewers. As a result, Doctor Who became a more mature, adventure-oriented programme featuring heavier doses of horror and violence.

Season Eight (1971): Enter -- The Master

Companions and Recurring Characters

Josephine (Jo) Grant was the Doctor's assistant during much of his tenure as UNIT's scientific advisor.

Katy Manning (bio) played Jo from Terror Of The Autons in January 1971 to The Green Death in June 1973.

Jo Grant

Captain Mike Yates of UNIT was Brigadier Lethbridge-Stewart's second-in-command for part of the Doctor's exile to Earth.

Richard Franklin (bio) played Yates on a recurring basis from Terror Of The Autons in January 1971 to Planet Of The Spiders in June 1974.

Captain Yates

The Master was a renegade Time Lord driven by a thirst for power at any cost.

Roger Delgado (bio) played the Master on a recurring basis from Terror Of The Autons in January 1971 to Frontier In Space in March 1973.

The Master

The Stories
Terror Of 
The Autons
Terror Of The Autons by Robert Holmes, directed by Barry Letts
The Doctor is warned of the arrival on Earth of a terrible new threat. The murderous renegade Time Lord known as the Master has stolen a Nestene energy unit and established a base of operations at a plastics factory where he has placed the owner, Farrel, under his mental influence. When the Doctor's new assistant, Jo Grant, stumbles upon the Master, she too is hypnotised, with orders to trigger a lethal trap for the Doctor. But this is not the only snare the Master has prepared for the Doctor, even as he plots a new Nestene invasion of the Earth. (This story has been recolourised, as the original prints are missing.)
With Liz Shaw having returned to Cambridge, Jo Grant is assigned to replace her.
The Mind Of 
Evil
The Mind Of Evil by Don Houghton, directed by Timothy Combe
At Stangmoor Prison, the Doctor and Jo attend a demonstration of the Keller Machine, which purports to remove the negative impulses from the human brain. However, when the Machine is activated, a man somehow dies as if he had suffered his greatest fear. Meanwhile, the Brigadier is responsible for security at the first-ever World Peace Conference, where Captain Chin Lee of the Chinese delegation is conspiring to undermine the negotiations. And, nearby, Mike Yates is preparing to escort a deadly nerve gas missile scheduled for disposal. Connecting all three events is the Master -- the evil mind behind the Keller Machine. (This story has been recolourised, as the original prints are missing.)
The Claws Of 
Axos
The Claws Of Axos by Bob Baker and Dave Martin, directed by Michael Ferguson
A mysterious spacecraft arrives on Earth, bearing beautiful, golden-skinned aliens who introduce themselves as Axons. They bring with them a fantastic substance called Axonite, which can affect the structure of matter. The Axons offer to provide the world with Axonite as a solution to world hunger and myriad other problems. The Doctor is suspicious, but his protests are overruled by a greedy ministry man named Chinn, who places UNIT under arrest. Meanwhile, Jo goes in search of US agent Bill Filer, who has become imprisoned within the spacecraft -- where his cellmate is none other than the Master.
Colony In 
Space
Colony In Space by Malcolm Hulke, directed by Michael Briant
When the Master steals information about a doomsday weapon, the Time Lords send the Doctor and Jo to the planet Uxarieus in the 25th century. There, they discover an Earth colony struggling with the twin perils of crop failure and death at the hands of what seems to be a monstrous lizard. Meanwhile, agents of the Interplanetary Mining Corporation have arrived on Uxarieus, asserting their right to drill for valuable duralinium. The Doctor must discover what connects these events with the Master -- and with the planet's primitive natives, who harbour a terrible secret.
The 
Daemons
The Daemons by Guy Leopold, directed by Christopher Barry
White witch Olive Hawthorne warns that dark forces are stirring in the village of Devil's End, where the Master is posing as the new vicar. The Doctor learns that Professor Horner, an archaeologist, is planning to open an ancient barrow near the community. He and Jo race to stop Horner, but they are too late and bizarre energies are loosed. A stone gargoyle prowls Devil's End, doing the Master's evil bidding, while the Brigadier discovers that an impenetrable heat barrier surrounds the town. But the Doctor is convinced that these phenomena are just pretexts to the arrival of a being older than humanity itself... (This story has been recolourised, as the original prints are missing.)

Making History

With the Doctor, Brigadier Lethbridge-Stewart and Sergeant Benton now joined by Jo Grant, Captain Yates and the Master, the “UNIT Family” of characters was complete, setting the stage for three years of remarkable stability under the guidance of Barry Letts and Terrance Dicks. Although the Doctor Who production team would later acknowledge that they had been unwise to use the Master in all five of the year's stories, resulting in a certain amount of predictability and overexposure, Season Eight nonetheless saw Doctor Who's popularity on the rise once again.

Season Nine (1972): A Galactic Yo-Yo

The Stories
Day Of The 
Daleks
Day Of The Daleks by Louis Marks, directed by Paul Bernard
Sir Reginald Styles is preparing to host a crucial international peace conference when he is attacked by a man with futuristic weaponry -- who suddenly vanishes. Soon thereafter, another guerrilla is murdered by brutish Ogrons. The Doctor decides to pose as Sir Reginald, and is soon confronted by more guerrillas. They come from the twenty-second century, and have travelled back through time to kill Styles because they hold him responsible for the devastation of their era. Jo inadvertently activates one of their time machines and finds herself catapulted into a future where the Earth is dominated by the Daleks!
The 
Curse Of Peladon
The Curse Of Peladon by Brian Hayles, directed by Lennie Mayne
The planet Peladon is attempting the join the interstellar Federation. Delegates from several worlds have come to meet with King Peladon -- including the Ice Warriors, led by Lord Izlyr. However, the high priest Hepesh warns that the King's plans are risking the anger of the mythical beast Aggedor. The delegates are saved from a falling statue only by the intervention of the Doctor and Jo, whom the Time Lords have sent to Peladon. When the life support system of delegate Arcturus is sabotaged, the Doctor suspects Izlyr. But are his past experiences with the Ice Warriors blinding him to the real villains?
The Sea 
Devils
The Sea Devils by Malcolm Hulke, directed by Michael Briant
Several ships have gone missing off the British coast, and the Doctor suspects an unnatural cause. Investigating an old sea fort at the epicentre of the disappearances, he comes face-to-face with the aquatic cousins of the Silurians, nicknamed Sea Devils. Like the Silurians, they have lain dormant for aeons in suspended animation, but have recently been awakened. But even as the Doctor starts to formulate a plan to achieve peace with the Sea Devil colony, the Master is plotting too. Having duped the governor of the prison where he is incarcerated, he now plans to help the Sea Devils destroy humanity.
The 
Mutants
The Mutants by Bob Baker and Dave Martin, directed by Christopher Barry
In the thirtieth century, Earth's decadent intergalactic Empire is in its dying days, but the cruel Marshal clings to power over the planet Solos. The Doctor and Jo arrive, tasked by the Time Lords with delivering a mysterious message. They learn that unrest on Solos is mounting as the Marshal tightens his grip, in defiance of orders from Earth to grant its people their independence. At his behest, the scientist Jaeger is conducting experiments to make the planet's atmosphere more suitable for humans. But the Solonians blame these trials for a virulent mutation, which is turning them all into hideous monsters.
The Time 
Monster
The Time Monster by Robert Sloman, directed by Paul Bernard
The Master obtains the Crystal of Kronos and uses it to construct a machine which lets him manipulate time. He succeeds in summoning an Atlantean priest named Krasis to the present day, but his experiments also alert the Doctor to his machinations. The Master's goal is to gain control of Kronos, a Chronovore native to the time vortex. But Krasis reveals that the Master only wields a fragment of the true Crystal, which is held in Atlantis by King Dalios. With the almost limitless power of Kronos within his grasp, the Master plunges back into antiquity -- and the Doctor has no choice but to follow.

Making History

With Doctor Who's popularity on the rise once again, the production team began to restore some of the elements which had been deemphasised since the start of the Pertwee era. The year would not only feature several trips in the TARDIS -- although the Doctor was still unable to operate it independently -- but also the return of old enemies like the Daleks and the Ice Warriors, in addition to the Master.

Season Ten (1972-73): A Return To Wandering

The Stories
The Three 
Doctors
The Three Doctors by Bob Baker and Dave Martin, directed by Lennie Mayne
UNIT headquarters is attacked a strange form of energy which the Doctor believes has been sent to target him. He sends a distress signal to the Time Lords, but their power is being drained through a black hole -- from which the attack on the Doctor also emanates. The Time Lords are able to send the Second Doctor to assist the Third Doctor, while the First Doctor advises them from the TARDIS scanner. The Doctors allow the energy to teleport them through the black hole into a world of anti-matter. There they discover Omega, an ancient Time Lord long thought dead, who now wields absolute power over his new domain.
Carnival Of 
Monsters
Carnival Of Monsters by Robert Holmes, directed by Barry Letts
With the Doctor once again free to wander in time and space, the TARDIS lands aboard the cargo ship SS Bernice. Jo believes that it is 1926, but the Doctor realises that the vessel is one which history records as having disappeared without a trace. The mystery deepens when a dinosaur attacks the Bernice -- after which the passengers and crew obliviously start to repeat their recent actions. The Doctor discovers that the ship is trapped inside a Miniscope: outlawed technology owned by a travelling showman named Vorg. But the Miniscope also houses the monstrous Drashigs, who threaten the lives of all those imprisoned within.
Frontier In 
Space
Frontier In Space by Malcolm Hulke, directed by Paul Bernard
The Earth Federation is on the brink of war with the rival Draconian Empire. When the TARDIS lands on an Earth spaceship in the midst of an ambush, the Doctor and Jo realise that the crew perceives the attackers to be Draconians when, in reality, they are Ogrons using a hypnotic device. Unfortunately, the brainwashing also convinces the humans that the Doctor and Jo are Draconian collaborators, and they are sentenced to spend the rest of their lives in a lunar penal colony. There they learn that it is the Master who's inflaming tensions between the two space powers. But why?
Planet Of 
The Daleks
Planet Of The Daleks by Terry Nation, directed by David Maloney
In pursuit of the Daleks who were working with the Master, the TARDIS materialises on Spiridon. Jo leaves the unconscious Doctor behind while she ventures into a hostile jungle, where she encounters a group of Thals. Returning to the TARDIS, they reveal to the now-recovered Doctor that their mission is to locate and destroy an army of ten thousand Daleks, hidden somewhere on Spiridon. Poisoned in the jungle, Jo is saved by Wester, one of the planet's invisible natives. The time travellers discover that the Daleks intend to learn the secret of the Spiridons' invisibility, rendering their army virtually unbeatable...
The Green 
Death
The Green Death by Robert Sloman, directed by Michael Briant
While the Doctor explores the planet Metebelis Three, Jo and the Brigadier travel to the Welsh village of Llanfairfach. Lethbridge-Stewart is investigating reports of a dead miner whose corpse glowed green, while Jo is interested in the work of Professor Jones, an ecologist who has established the nearby Wholeweal community. The Brigadier is rebuffed by Stevens, the director of Global Chemicals, who receives orders from a mysterious boss. Convinced by Jones that Global's waste is poisoning the local mine, Jo investigates. She discovers that it is crawling with insects -- mutated into giant, green monsters.
Jo leaves UNIT to marry Professor Jones.

Making History

Doctor Who's milestone tenth season was celebrated in several ways: The Three Doctors brought together all three Doctors -- William Hartnell, Patrick Troughton, and Jon Pertwee -- against the menace of the mad Time Lord, Omega, while the combined narrative of Frontier In Space and Planet Of The Daleks was intended to challenge Season Three's The Daleks' Master Plan as the longest Doctor Who story ever. However, Season Ten was most notable for restoring the programme's original format, as the Doctor's exile to Earth was rescinded and he became a wanderer in space and time once again. Together with the departure of Katy Manning at the end of the year, and the tragic death of Roger Delgado in an automobile accident, this decision initiated the dissolution of the UNIT Family, and heralded the beginning of the end of the Pertwee era.

Season Eleven (1973-74): Facing Fears

Companions and Recurring Characters

Sarah Jane Smith was a journalist who stowed away aboard the TARDIS during an investigation. Even after leaving the Doctor, she continued defending Earth from alien invasion with the help of a group of teenagers and the robot dog K·9.

Elisabeth Sladen (bio) played Sarah Jane from The Time Warrior in December 1973 to The Hand Of Fear in October 1976.

Sarah Jane Smith

The Stories
The Time 
Warrior
The Time Warrior by Robert Holmes, directed by Alan Bromly
UNIT is called in when scientists begin disappearing from a top-secret research establishment. The Doctor discovers that they are being abducted into the past, and uses the TARDIS to follow them through time -- not realising that he has a stowaway aboard in the form of journalist Sarah Jane Smith. Arriving in the Middle Ages, the Doctor tracks the missing scientists to the castle of a warlord named Irongron. There he discovers that Irongron is in league with a Sontaran, Linx, who has crashlanded on Earth, and is now supplying the alien weaponry with which Irongron is terrorising the English countryside.
Having helped the Doctor defeat Linx, Sarah Jane is invited aboard the TARDIS.
Invasion Of 
The Dinosaurs
Invasion Of The Dinosaurs by Malcolm Hulke, directed by Paddy Russell
The Doctor and Sarah return to the present day, only to discover that London is all but deserted. Arrested as looters, they are attacked by dinosaurs while being taken to jail. Reunited with UNIT, the Doctor realises that a device is being used to terrorise the city by reaching into the Earth's past. He formulates a plan to track down those responsible -- unaware that Captain Yates is part of the plot, and has been tasked with sabotaging the Doctor's scheme. Meanwhile, Sarah Jane is ambushed while investigating a possible lead. She wakes up to find herself on a spaceship... which left Earth months earlier! (Episode one has been recolourised, as the original print is missing.)
Death To The 
Daleks
Death To The Daleks by Terry Nation, directed by Michael Briant
The TARDIS suddenly loses power, and the Doctor and Sarah emerge to find themselves trapped on the planet Exxilon. They meet a crew from Earth which has come to Exxilon seeking parrinium, which is needed to cure a virulent space plague. However, the humans are affected by the power drain, too -- as are the Daleks, who have also arrived in search of parrinium. The humans, the Daleks and the time travellers forge an uneasy alliance against the violent natives of Exxilon. But the Daleks are already plotting betrayal, and the Doctor is left with no choice but to venture into the Exxilons' forbidden city in search of answers.
The Monster 
Of Peladon
The Monster Of Peladon by Brian Hayles, directed by Lennie Mayne
The TARDIS returns to Peladon fifty years after its first visit, and Queen Thalira, daughter of King Peladon, is now the head of state. The Galactic Federation desperately needs trisilicate -- in which Peladon is rich -- to wage a war against the oppressive Galaxy Five. But this has sparked dissension amongst Peladon's miners, inflamed by the manifestation of the ghost of Aggedor, the Sacred Beast of Peladon, to condemn the Federation. As Chancellor Ortron schemes for power, Alpha Centauri is convinced to summon help. When the Ice Warriors arrive, the Doctor is again suspicious of them; but is he repeating past mistakes?
Planet Of 
The Spiders
Planet Of The Spiders by Robert Sloman, directed by Barry Letts
Mike Yates summons Sarah to a meditation centre, where he believes a man called Lupton is up to no good. In fact, Lupton has gained fantastic powers after bonding with one of the Spiders who rule the planet Metebelis Three. Their mission is to find the blue crystal which the Doctor stole from Metebelis Three, and recover it on behalf of the mammoth Great One. Sarah is teleported to the Spiders' planet, where she finds a regressive human colony living in fear. The Doctor has no choice but to follow her -- setting the stage for an encounter with the Great One that will change his life forever.
Suffering from fatal radiation poisoning, the Doctor regenerates into his fourth incarnation.

Making History

With Richard Franklin leaving Doctor Who this season, and Barry Letts and Terrance Dicks finally prepared to dissolve the long-standing production team, Jon Pertwee himself decided to leave the series, a decision also mitigated by an unwillingness by the BBC to increase the actor's salary. As a result, perhaps the most stable era of the show's history ended on a high note, with the programme's popularity still soaring. But the heights Doctor Who had reached thus far were nothing compared to those it would soon attain...