The Master (Terror of the Autons)

The incarnation of the Master that was, according to most accounts, the penultimate incarnation of his original regeneration cycle, went on to fight various battles against the Third Doctor and UNIT during the Doctor's exile on Earth, even spending a short period also trapped on the planet until he retrieved his stolen dematerialisation circuit from the Doctor.

After the Doctor foiled his attempt to ally with the Dæmon Azal, the Master was arrested by UNIT Sergeant John Benton. With the government using him as a scapegoat to cover up recent extraterrestrial incursions, the Master was moved to various prisons until he was finally imprisoned on Fortress Island as the sole inmate, but he was eventually able to orchestrate his escape with the aid of the Sea Devils.

After growing tired of his conflict with UNIT, the Master formed an allegiance with the Dalek Empire to start a war between Earth and Draconia. After his plan was foiled by the Doctor, the Master was either rendered into a wasted state by Susan Foreman or forced to regenerate after a battle with the Twelfth Doctor in a time locked dimension.

Origins as "Koschei"
According to some accounts, after he left Gallifrey the Doctor's old friend originally travelled under the name of "Koschei", having yet to take on the name of "the Master" and embark on his crusade of evil and conquest. (PROSE: The Dark Path, The Face of the Enemy, Rebel Rebel) Chris Cwej once met a "Koschei" with green eyes and a dark beard. (PROSE: Rebel Rebel)

Koschei would ultimately lose his moral grip, and take on the name of "the Master", having been betrayed by his companion Ailla and then left to die in a black hole by the Second Doctor after he tried to abuse the power of the Darkheart. Throughout these events he had, by then, been in a physical form identical (PROSE: The Dark Path) to the form he would go on to wear as the Master in his rivalry with the Third Doctor, (TV: Terror of the Autons, etc.) but his encounter with the Second Doctor seemed to end in this body's apparent death and the loss of several regenerations to the Darkheart, suggesting that they may not have technically been the same incarnation; (PROSE: The Dark Path) the Master proper would indeed claim that Koschei had "died". (PROSE: The Face of the Enemy)

Early schemes
The Master penetrated Gallifrey, and gained access to the Matrix via a console in the old Capitol. This gave him a backdoor into the Matrix, which he used to collect classified information for his many devious schemes, (PROSE: The Quantum Archangel) including the Time Lords' files on the Doomsday Weapon, (TV: Colony in Space) the Sea Devils, (TV: The Sea Devils) the Chronovores, the Dæmons, (PROSE: A Brief History of Time Lords) and the Deathworm Morphants. (PROSE: The Quantum Archangel)

The Master then put his TARDIS in orbit of the homeworld of the Archons and made a deal with them that would result in the Archons acquiring the Doctor's TARDIS for themselves. Posing as "Professor Thascalos", the Master gave the Necronomicon to the Doctor's companion Jamie McCrimmon, so that Jamie would give the book to the Doctor and lure the TARDIS to the Archon homeworld. (PROSE: The Nameless City)

The Master forced Moses, a sculptor, to serve him. He brought him to the planet Djinn and kept him prisoner, forcing him to make masks for him. (PROSE: A Master of Disguise)

Early times on Earth
According to one account, the Master was imprisoned on Shada by the Time Lords at the time when the Doctor was exiled to Earth. However, the Celestial Intervention Agency arranged for the wardens of Shada to release him so as to keep the Doctor busy. Because they believed he would make short work of an unaware Doctor, they sent a messenger to forewarn the Doctor of the Master's arrival. (PROSE: Prisoners of the Sun) Having learned that the Doctor was exiled on Earth, the Master decided to invade it. (PROSE: The Secret Diary of the Master)

According to another account, by the same time the Master arrived on Earth, the Time Lords still hadn't managed to recapture him since the occasion when he had "slipped away" from them before his timeship could be de-energised. The Time Lords had picked up his trail on their monitor, but lost the signal due to a mysterious alien interference. In defeat, the Time Lords sent one of the High Council to Earth in person to warn the Third Doctor that the Master was coming. (PROSE: Doctor Who and the Terror of the Autons)

The Master was present at the first Auton invasion of Earth, and heard about Channing's attempt to capture the Third Doctor. He contacted journalist James Stevens by phone, whose article he had read in the Daily Chronicle, and told him about the near-kidnapping. He called Stevens again during the Silurian attacks on Wenley Moor, informing Stevens that Edward Masters had been the first to die from the plague sweeping London. Shortly after the Inferno Project incident, the Master once more contacted James Stevens, this time to check up on his work on his UNIT article. He promptly hung up when Stevens mentioned C19 and the Glasshouse. (PROSE: Who Killed Kennedy)

Under the alias "Emil Keller", the Master captured a psychic parasite and trapped it within the Keller Machine, and spent many months establishing "Keller" and the machine's credentials. (TV: The Mind of Evil)

The Master first infiltrated the headquarters of UNIT while the Brigadier and the Doctor had gone to meet with government officials. He hypnotised the Doctor's assistant, Liz Shaw, and, through her, learnt of the failed Nestene invasion and the awakening of the Silurians. This inspired him to ally himself with the Nestene and to locate more Silurian colonies. (PROSE: Reconnaissance)

Becoming a threat
The Master appeared at the International Circus, with his TARDIS in the form of a horse box. He hypnotised the circus troupe and plastic factory manager Rex Farrel to obey his orders as part of his plan to assist the Nestenes in their latest bid to conquer Earth. A Time Lord emissary alerted the Doctor to his rival's presence on the planet, and before the radio telescope could be used to bring the Nestene invasion force to Earth, the Doctor convinced the Master that the Nestenes would not distinguish between the Master and anyone else in their takeover, and the two worked together to fling the Nestenes back into space by "chang[ing] the polarity" whilst the radio telescope's transfer shift was still open. Afterwards, the Master fled. The Doctor, however, had already taken his dematerialisation circuit, preventing the Master from leaving Earth in his TARDIS. (TV: Terror of the Autons)The Master returned again, posing as the scientist who had "developed" the Keller Machine. He used prisoners as a plan to hijack the Thunderbolt, a missile containing nerve gas and use it to destroy the World Peace Conference, which would trigger a nuclear war. The Doctor, with the help of Barnham, stopped the Master with the Keller Machine, and the Doctor reactivated the missile's abort mechanism. UNIT also destroyed the missile along with the Keller Machine, but the Doctor later discovered he had lost the Master's dematerialisation circuit in his altercation with the Master. Shortly after, the Master telephoned to let it be known that he had found the circuit and was free now to come and go as he pleased, while the Doctor had to remain in exile. (TV: The Mind of Evil)

Shortly after the Master regained control over his TARDIS, he tried to gain control of a cult so he could harness the power of the Immortals. He convinced the real cult leader, Hadley, that he could serve the cult loyally, by supplying them with sarg. Unfortunately for the Master, Hadley only intended to keep the Master alive while he was still useful. With no other options, the Master formed a temporary truce with the Doctor to stop Hades' plan. After the crisis was resolved, the Doctor allowed the Master to depart unmolested in the name of their temporary truce. (PROSE: Deadly Reunion)

The Master brought Axos to Earth, hoping to ally himself with them. Instead, he became the prisoner of Axos, and only escaped by saying that he would help it. The Doctor tricked the Master into thinking he was going to betray Earth. Instead, he trapped the Master with Axos in a time loop. (TV: The Claws of Axos) Posing as an Adjudicator, the Master travelled to a human colony on the planet Uxarieus in the year 2472. There, the Time Lord records indicated he would find the Doomsday Weapon created by a near-extinct native species. Once again the Doctor defeated his plans and the weapon was destroyed. (TV: Colony in Space)

Posing as a vicar named "Victor Magister" in the village of Devil's End (TV: The Dæmons; PROSE: Who Killed Kennedy) after murdering the old vicar, Canon Smallwood, (PROSE: The Eight Doctors) the Master summoned the ancient Dæmon Azal, but he failed to understand the power and control that was necessary following summoning him. Following Azal's confrontation with Jo Grant's selflessness, Azal destroyed himself through Jo's illogical actions. The Master was captured by UNIT following a failed attempt to escape in the Doctor's car, Bessie. (TV: The Dæmons)

In custody
Prior to his trial, the Master was sent to Stangmoor Prison. During his captivity, an army of hypnotised salespeople stormed the facility and attempted to rescue him, but the ploy failed and the Master was sent to another secure holding facility. Meanwhile, the Doctor and Jo were trapped in an extra-universal prison by the Freedom Corporation, so the Brigadier was forced to strike a deal with the Master to save them. But the Master double-crossed him and used time travel technology to regress the Earth backwards in time. However, with help from the Time Lords, the Doctor was freed and was able to stop the Master's plan and restore everything to normal. (PROSE: Freedom)

At his trial, the government used the Master as a scapegoat for all the alien attacks which had recently occurred. (PROSE: Who Killed Kennedy)

The Master was held at Aylesbury Grange Detention Centre. Demanding the Doctor visit him, he engaged the Doctor in conversation, insisting he had changed. However, the Doctor refused to believe him, and the Master reluctantly revealed that he had drawn the Doctor to the facility as part of an escape attempt and that the Doctor was speaking to a hologram. The Master nearly escaped but was stopped by UNIT soldiers accompanying the Doctor, who revealed he had been a hologram as well. (COMIC: The Man in the Ion Mask)

In another escape attempt, the Master created a device that switched his mind with the Doctor's. He went to the Doctor's TARDIS, where he learned that the Time Lords had made the TARDIS ineffective to the Doctor's piloting. Before returning to his own body, he asked the Brigadier to move him to a new holding facility with a good view, and also encouraged Mike Yates to ask Jo Grant out on a date. (PROSE: The Switching)

While in custody, with the Doctor on Peladon, (TV: The Curse of Peladon) the Master collaborated with UNIT to prevent an invasion by a fascist version of Earth, travelling with the Brigadier, Ian and Barbara Chesterton to the alternate universe and encountering Koschei, the alternate version of himself. Koschei was imprisoned and tortured by order of the Leader of the Republic of Great Britain. The Master killed his other self, claiming it was an act of mercy. Before he was imprisoned by UNIT again, the Master hid his TARDIS back in the church crypt in Devil's End. (PROSE: The Face of the Enemy)The Master was imprisoned inside a castle prison on Fortress Island as the only prisoner. The Master convinced his jailer, Colonel George Trenchard, to help him steal electronic parts from HMS Seaspite, telling Trenchard that this was intended as a lure for enemy agents. With these parts, the Master instead made contact with the reptilian Sea Devils, an aquatic species similar to the land-dwelling Silurians, and planned to cause a war between humans and Sea Devils, making the Sea Devils rulers of Earth again. Because the reactivation machinery of the Sea Devils' hibernation units deteriorated during millions of years of hibernation, the Master saw it necessary to construct a sonar device to awaken the remaining reptiles.

The Master captured the Doctor and forced him to help create this device, but to prevent the device from reactivating further Sea Devil bases and stop the war, the Doctor blew up the Sea Devil base by reversing the device's polarity, creating a massive reverse feedback. The Master escaped in a hovercraft when the officer guarding him, CPO Myers, was hypnotised and framed as the Master's corpse, (TV: The Sea Devils) and the Master returned to the church crypt in Devil's End to retrieve his TARDIS. (PROSE: The Eight Doctors)

At large again
Sometime after his escape, the Master took control of the Glasshouse, a facility for traumatised UNIT soldiers, taking particular control of Private Francis Cleary. He planned to use a Time Ring to have Cleary go to 1963 to prevent the assassination of John F. Kennedy, thereby altering Earth's history to make it more vulnerable to invasion. The plan failed. (PROSE: Who Killed Kennedy)

On another occasion, the Master made a deal with the Odobenidans to help them invade Earth, but accidentally trapped both them and himself in a time loop whilst undertaking some temporal mechanics on their behalf. He was trapped in the time loop beneath Greece for months. The Doctor, sent to Greece by the Time Lords to deal with the time loop, released the Master and foiled his plan. (PROSE: The Seismologist's Story)

The Master discovered the mind parasite known as the Nurazh on a desolate planet. Weakened, the creature failed to take control of him, and begged him to take it off the planet. The Master agreed, taking it to the UNIT hospital Kenstone Hall, where he planned to have it take control of the invalids, healing their injuries in the process, in order to give him an army of brainwashed slaves. The Nurazh, secretly planning to devour the Earth, eventually turned on the Master, who was last seen ducking into his TARDIS after releasing Jo Grant from the Nurazh' s control. (PROSE: The Touch of the Nurazh)

After being double-crossed by the Voords, (PROSE: The Quantum Archangel) the Master posed as "Professor Carl Thascalos" and constructed a machine known as TOMTIT at Cambridge's Newton Institute to summon the ancient chronovore Kronos, whom he wished to control. He hypnotised the institute's director, Dr Charles Percival, but accidentally killed him by releasing Kronos from the Crystal of Kronos. The Master summoned the Atlantean priest Krasis for instructions on how to control Kronos while meddling with the flow of time to obstruct the Doctor from getting in his way.

After knocking out Sergeant Benton, the Master retreated to his TARDIS, but the Doctor tried to trap him in a time lock using his own TARDIS, accidentally creating a space loop when both TARDISes were materialised within the other. When the TARDISes were separated during their negotiations, the Master ejected the Doctor into space, but the Doctor survived by using the telepathic circuit of his TARDIS to help Jo return him to safety.

The Master travelled to ancient Atlantis and failed to hypnotise King Dalios, who easily resisted his influence. Confronting the Doctor there, the Master tried to manipulate Queen Galleia into betraying her husband, since she had taken a romantic liking in his charm compared to Dalios' dull personality. Galleia, however, was enraged when the Master caused Dalios to die in the coup they staged in Atlantis. Before he was arrested, the Master commanded Krasis to use the Crystal of Kronos housed in Atlantis and brought forth Kronos, who destroyed the entire civilisation.

Fleeing Atlantis with Jo as his hostage, and with Kronos under his control, the Master was in a position to cast destruction unto the entire cosmos, however, the Doctor threatened to time ram the Master's TARDIS with his own, which would take everyone's lives in the process if he did not give up his plans for chaos. The Master did not believe the Doctor would earnestly carry out his warning because he knew endangering Jo's life was not an option for him. In response to the Doctor's hesitation, Jo tried to complete the time ram before the Master could release Kronos again. Instead, Kronos spared everyone from death, and captured the Master for the crime of trying to control it, but allowed him to go free at the request of the Doctor. (TV: The Time Monster)

The Master set up a talent show called Make a Star, based on the anagram "AKA MASTER", which he used to disrupt the timeline by making the contestants cover songs that weren't yet written. He intended to use the relatively minor disruption caused to allow him to take control of Earth, but this plan was foiled by the Third Doctor and Jo Grant. (PROSE: Hidden Talent)

When a race of mechanical lifeforms invaded Earth, the Master, intrigued by a species he knew nothing about, and insulted that they hadn't requested his aid in their invasion, began investigating them. When the Second Doctor showed up, the Master discovered that he was in fact Ramón Salamander. After a few false starts, the Master allied with the Doctor and UNIT to thwart the human's scheme. After travelling back to 1868 with them, the Master took control of the micro machines, intending to use them for galactic conquest before the Doctor overrode the Master's command protocols. Accepting his defeat, the Master ran back to his TARDIS and escaped. (COMIC: The Heralds of Destruction)

Following the Doctor's TARDIS to 25 December 2006, the Master learnt that the Earth was being invaded by the Sycorax, whom he intended to ally with so he could enslave the planet himself. Arriving at 48 Bucknall House at the Powell Estate, the Master was trapped by tinsel controlled by the Roboforms after stepping out of his TARDIS. After an hour listening to The Twelve Days of Christmas played by a broken snowman ornament, the Master was found by the Doctor, Jo, Yates and Jackie Tyler. Deeming that the Master had suffered enough, the Doctor set him free to take his leave in his TARDIS. (PROSE: The Christmas Inversion)

The Master attempted to steal the Crown Jewels but was confronted by the Doctor, Jo and the Brigadier. (AUDIO: Masterful)

Distancing himself from UNIT
The Master travelled to the Land of Fiction, where he intended to steal an advanced piece of technology from the Land, and defeated Professor Moriarty, (COMIC: Character Assassin) and became involved in "a galactic fracas" relating to "a number of large tortoises". The Doctor and Jo put a stop to this scheme. (AUDIO: The Last Fairy Tale) He attended Bonjaxx's birthday party at Maruthea. When a fight broke out, the Master was seen crouching to avoid the confrontation, evidently annoyed. (COMIC: Party Animals)

The Master used time-displaced Scottish warriors to seize a nuclear submarine and threaten Britain with obliteration if he wasn't given the Doctor's TARDIS; he ended up temporarily trapped in the 18th century. (COMIC: The Glen of Sleeping)For a short while, the Master adopted the identity of "Duke Dominus", a gangster on early 20th century Earth, but his plan was foiled by the Fourth Doctor without either realising the others' involvement. (PROSE: The Duke of Dominoes)

The Master travelled to a Sontaran-occupied planet and convinced several of the locals that he was a deity. This would form a new sect of proud, beard-toting column-worshipping Sontarans, which would decades later lead to the destruction of the entire planet by Sontaran command. The Master left decades before this, delighted simply by the idea of the chaos he had created. (COMIC: The Judas Goatee)

The Master tracked down a fellow Time Lord renegade, the Minister, on the planet Samael, where she was one of the most eminent political figures. Taking advantage of her post-regenerative weakness, the Master attacked her psychically and caused her amnesia; then, he brainwashed her and tried to convince her to give him power over the planet. His plan was foiled by Jo, who helped the Minister remember who she was. (AUDIO: The Same Face)

Final exploits
The Master planned to release a fog in Tadcaster by using Sarkan mist-flowers to generate a fog that would engulf the Earth in a dense fog. Attempting to catch up with the Master, the Doctor commandeered a pier train that crashed into the Master and the mist-flowers, sending all of them into the ocean, where the flowers were destroyed and the Master disappeared. (COMIC: Fogbound)

Reappearing again, the Master took control of the Brigadier's mind and instructed him to kill the Doctor. However, the Brigadier attacked the Master, but he escaped, restoring the Brigadier to his senses. (PROSE: Smash Hit) Having had enough of Earth, and having other plans to set in motion on Skaro, the Master employed the assistance of a being called Verdigris to impersonate him. (PROSE: Verdigris) On Skaro, the Master forged an alliance with the Daleks, presenting a proposal for what was designated Operation Divide and Conquer to the Dalek Supreme Council, (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe) led by the Emperor's second-in-command. (PROSE: Doctor Who and the Planet of the Daleks) The Emperor himself approved the plan involving the Master when the Daleks presented it to him. (AUDIO: The Dalek Conquests) The Master acted as the Daleks' agent to provoke warfare between the Earth Empire and the Draconian Empire in the 26th century. To achieve this, he employed a force of Ogrons who, through the use of hypnosound, made themselves appear human or Draconian, thus provoking the other side. When the Doctor revealed the true perpetrators, the plot was abandoned. (TV: Frontier in Space)

The Master brought a Skaross to Earth, and with its help disguised himself as "Professor Derek Drake", a scientist pretending to have found a way to solve the Earth's energy crisis and pollution problem. The telepathic power of the Skaross allowed the Master to gain the support of the public opinion, appearing numerous times on television, and even managed to confuse the Doctor for a while; the creature, however, proved to be very reluctant to obey the Master, and more than capable of resisting against his own psychic power. When it became evident that the Doctor had caught up to the ruse, the Master went to UNIT HQ and he and the creature offered to help humanity, but the Doctor refused, and instead gathered the Master had come to ask for his help against the Skaross. Eventually, the Master gained access to the main reactor of a nuclear station, intending to blackmail the world by using the Skaross' ability to control carbon dioxide, but the Skaross instead tried to convert Earth into a world it could live in. The Doctor and the Master then fought against it together, and won, connecting themselves with a telepathic link, which allowed them to see each other's thoughts. The Master then escaped in his TARDIS. (AUDIO: Terror of the Master)

The Master tried to rob the Repository on a water planet to retrieve from his Vault a map to the Boneyard of Knives. In doing so, he used a de-evolutionary gun he took from a jungle planet to kill the guards, by reducing them to a previous state in evolution; however, the new forms of life proved to be personality leeches, and started to feed on him. The Master barely managed to get back to his TARDIS and leave a message to himself to recover from his memory loss and instructed himself to use the map to find the Boneyard, before collapsing to the ground and losing consciousness. (AUDIO: Master Thief)

The Master tried to take control of the Hyrrokin dimension, but his plan failed and he was imprisoned for three years and two months. A Hyrrokin judgment biomechanoid, Loge, made a deal with him: he would give him back his TARDIS, if he helped him to retrieve three outlawed Hyrrokin warlords, Narvi, Siarnaq and Karta, who escaped to Earth and lived there disguising as human beings, so they could face justice. The Master agreed, and together with Loge tracked down the three warlords, awakened their memories and brought them on a spaceship. There, he found out Loge deceived him: he was not bringing the warlords to justice, he was returning them to their dimension so they could conquer it. Loge and the warlords tried to dispose of the Master, but he managed to kill Loge with the Tissue Compression Eliminator and used a psychic transporter to get the warlords off their ship, thus killing them. He then used Hyrrokin technology to retrieve his TARDIS and leave. (PROSE: Anger Management)

An agent of the Celestial Intervention Agency, Straxus, used a time ram to force the Master's TARDIS outside of the universe, intending to erase him from existence. In his damaged ship, the Master was exposed to the heart of the TARDIS which enabled an entity of his self-doubts to manifest, taking the form of the Third Doctor. The heart's energies gave the Master and the entity glimpses of possible futures in which he turned to desperate means to survive, even abandoning his Time Lord biology. The Master came to accept he would do anything to survive and used the heart to return to the universe, a feat Straxus believed impossible. The Master subsequently located Straxus and shot him. (AUDIO: The Threshold)

Meeting his end
According to one account, the Master used files he uncovered from the Daleks to go undercover on Earth following the 22nd century Dalek invasion, seeking a matter transmuter the Daleks built. As his scheme took a while to mature, the Master decided to stave off boredom by meddling in local politics under the name of "Estro", and schemed to create a war between Haldoran's forces and Lord London's. As he finally prepared to seize the matter transmuter, he found that Susan Foreman had gotten there before him. Though he failed to recognise her as the Doctor's granddaughter, he got the impression that she was at least one of the Doctor's former companions, and took her with him as a hostage back to his TARDIS. During a confrontation with the Eighth Doctor, who discovered his presence, he shot at him, but instead killed David Campbell, Susan's husband. The Master fled in his TARDIS together with Susan. As his TARDIS materialised on Tersurus, Susan awoke from her shock-induced torpor and, with her mental abilities amplified by the telepathic circuits of the Master's TARDIS, focused all of her hatred and grief into a force that "burned away" the Master. Believing she had weakened him into harmlessness, Susan forced the Master out onto Tersurus's surface, planning to strand him there. She also planned to use the Time Compressor Eliminator to destroy the matter transmuter; the Master furiously clung to the device, refusing to let go even when she warned him that she would shoot it. The blast that resulted from the TCE hitting the matter transmuter nearly killed the Master and left his body as deformed as his mind. Believing him dead, Susan departed in his TARDIS, but her use of it alerted the Time Lords to the Master's presence on Tersurus. Investigating the materialisation of an unauthorised TARDIS, the Time Lord Chancellor Goth arrived on Tersurus, where he found the Master in a wasted condition. (PROSE: Legacy of the Daleks)According to another account, the Master detected a massive discharge of temporal energy. He watched as the Twelfth Doctor's TARDIS exploded in 1972 (COMIC: The Pestilent Heart), and wrongly speculated this was the cause of the Doctor's third regeneration. (COMIC: Doorway to Hell) When the Doctor moved in with Jess Collins' family in Brixton and brought the TARDIS into the back garden to repair itself, (COMIC: Moving In) the Master plotted to use the artron energy given off by the regenerating TARDIS to create a portal to a time locked dimension he learnt about in the Dalek databanks. When the TARDIS had healed in 1973, the Master utilised the efforts of Katya Dabrowski to bring the Collins family to an apartment in central London, while creating a diversion for the Twelfth Doctor in Barking with glass mosquito creatures. The Master tricked the Collins family into being scanned for damage, when he actually used them to create a portal to the dimension which they were also sent through, while stealing the Doctor's TARDIS and linking it to his own, in order to aid the Doctor through the time lock. Travelling to the locked dimension, the Master met Kiadine, a being who once split the chronon, and was locked away by the Time Lords for this. He gave the Master his powers so that he would conquer Gallifrey on his behalf: his exposure to the chronon storm gave him god-like powers, and he began to fight with the Doctor for mastery of them. The Master fired one final attack as the Doctor stood arm in arm with the Collins family, and found that his attack had been repelled back at him with the artron energy in the bodies of the Collins family. Though battered from the attack, the Master was able to escape in his TARDIS and regenerated while declaring his intent of revenge on the Doctor. (COMIC: Doorway to Hell)

Post-mortem
When the was stripped of his Trakenite body by the Time Lords, and after his plot to steal the Fifth Doctor's regenerations failed, he found himself confronting mental projections of all his past incarnations, and was able to steal a bit of life energy from each of them, allowing him to regenerate back into his Trakenite body. (PROSE: The Velvet Dark)

While explaining to Alice Obiefune how time worked different during the Last Great Time War, the briefly turned back into his "UNIT era" incarnation. (COMIC: Kill God)

The "UNIT era" Master's voice was heard by the War Master whilst he was still under the powers of the Chameleon Arch, telling him to "destroy" his human persona, and return "[his] power" back to him. (TV: Utopia)

Undated events

 * The Master travelled with Finsey, a woman who was fascinated by his evilness, until he saw no further use for her and tried to have her killed. (AUDIO: The Transcendence of Ephros)

Psychological profile
As the rival of the Third Doctor, the Master was often arrogant and impatient, taken to be rude towards all and showing no tolerance for stupidity. (TV: The Dæmons, The Sea Devils, The Time Monster, Frontier in Space) To sway others to his way of thinking, the Master acted as a suave and debonair gentleman, with a sardonic sense of humour. (TV: Terror of the Autons, The Time Monster) When his own survival was at stake, the Master would not hesitate to betray his allies to save himself. (TV: The Claws of Axos)

The Master was willing to play the long game, spinning a web of lies while maintaining several back-ups in his schemes. (TV: The Mind of Evil) He seemed to truly believe his delusions of grandeur, proclaiming that he and the Doctor could "reign benevolently," ending "war, suffering [and] disease," (TV: Colony in Space) and that, instead of "all this talk of democracy, freedom, [and] liberty", the world needed "strength, power and decision." (TV: The Dæmons) When the Doctor accused him of being paranoid, the Master stated that everyone was paranoid, he was just honest about his paranoia. (TV: The Time Monster)

The Master held himself in high-esteem, even believing himself immune to the mind parasite within the Keller Machine, when in truth, he was only able to resist its attack on him for a short time, and with great effort. (TV: The Mind of Evil) He also demonstrated a strong confidence in himself when he walked into the UNIT HQ on the edge of London without fear of capture, instead hypnotising a handful of UNIT personnel. (TV: The Claws of Axos)

The "UNIT era" Master also had a juvenile side to him, making blithely sarcastic comments about an impending nuclear meltdown, (TV: The Claws of Axos) enjoying an episode of Clangers in his prison cell, (TV: The Sea Devils) and reading The War of the Worlds while trying to instigate a war between Earth and Draconia. (TV: Frontier in Space) He also had a sadistic side, taking particular pleasure in goading the Brigadier into attacking Axos when they both knew that it would put the Doctor and Jo Grant in danger. (TV: The Claws of Axos) He also took considerable delight in blackmailing the Doctor and Jo on Uxarieus. (TV: Colony in Space)

While he thought killing to be a sign of poor preparation and unprofessionalism, (PROSE: The Dark Path) the "UNIT era" Master would casually murder those whom he could not control, (TV: Terror of the Autons) or who were standing in the way of an item he required. (TV: The Claws of Axos) While he initially believed that those who died as a result of his schemes to be "necessary sacrifice[s]", (TV: The Sea Devils) he came to see killing "pawns" as "the only way to win" by the end of his life, even resorting to murder simply as a demonstration of power. (COMIC: Doorway to Hell)

Unlike his following incarnations, the "UNIT era" Master was rarely resentful, instead accepting defeat with only a slight annoyance, (TV: The Dæmons, Frontier in Space) though he once stated that destroying the Doctor's favourite species would "be a reward in itself". (TV: The Sea Devils) The Master also learned from his mistakes, placing an alarm in his TARDIS (TV: Colony in Space) after the Doctor stole his dematerialisation circuit. (TV: Terror of the Autons)

Being a haughty psychopath, he regarded most beings as his inferiors, but had a mutual respect for the Doctor as a worthy opponent and his near intellectual equal, (TV: Terror of the Autons, The Sea Devils) and even showed a certain respect to the Doctor's companions, even if he still considered them inferior. (TV: Frontier in Space) He often found himself unable to kill the Doctor, because that would rid him of the satisfaction of defeating him, (PROSE: Legacy of the Daleks) and would only resort to killing the Doctor if he viewed him as an unmovable obstacle in his plans, (TV: Terror of the Autons) considering his quarrel with the Doctor to be something of a game, though he was willing to risk the Doctor's life on the Keller Machine to satisfy his curiosity. (TV: The Mind of Evil) However, the Master was not above working alongside the Doctor when necessary, (TV: The Claws of Axos) and even offered to rule the universe with him. (TV: Colony in Space)

While in Atlantis, the Master formed a relationship of sorts with Queen Galleia, remarking that she was beautiful and promising her power. Both Galleia and Lakis commented that the Master had "the bearing of a God". (TV: The Time Monster)

The Thirteenth Doctor remarked that, while he was still "evil", the "UNIT era" Master had been "an old charmer". (PROSE: The Doctor vs the Master)The "UNIT era" Master would occasionally smoke a cigar. (TV: The Mind of Evil, The Time Monster)

A master manipulator, the Master knew how to use others' greed and sense of duty as bargaining tools in his schemes, (TV: The Claws of Axos, The Sea Devils) and how to use his authority as an adjudicator to manipulate and influence the human factions and their competing aspirations on Uxarieus. (TV: Colony in Space)

The Master was also stronger than he appeared, as he was able to physically overpower Luigi Rossini, (TV: Terror of the Autons) Harry Mailer, (TV: The Mind of Evil) Smedley, (TV: The Sea Devils) and John Benton. (TV: The Time Monster) He was also able to make a small jump onto a moving lorry from a bridge, and then swing down to the driver's cab to hypnotise the driver. (TV: The Claws of Axos)After an attack he made on the Twelfth Doctor was sent back at him, the Master, claiming he would get his revenge on the Doctor, proudly welcomed his regeneration, declaring that death was meaningless to him and that "all life [would] obey [him]". (COMIC: Doorway to Hell)

Appearance
The "UNIT era" Master resembled a mature, elegant man, with a swarthy complexion, brown eyes, and mild streaks of grey in his combed back thinning hair. He had a goatee beard, which also had white skunk stripes. He generally wore an ebony black Cardin-Nehru jacket, with dark trousers, black leather boots and gloves, and a ivory cuff-linked shirt. (TV: Terror of the Autons) On occasion, he would wear a suit, with either an orange, grey or blue tie. (TV: Terror of the Autons, The Mind of Evil, The Time Monster)

While imprisoned on Fortress Island, the Master wore a black cape over a white turtle-neck jumper, with black trousers, but switched these for a naval officer's uniform while secretly infiltrating HMS Seaspite. During his return and subsequent escape from Fortress Island, he changed back into his black Nehru jacket and trousers. (TV: The Sea Devils)

The Master's UNIT file described him as "a guy of swervey complexion, with a goatee and a reseeding hairline." (AUDIO: Mastermind) remembered him as "the Beardy One". (PROSE: Meet Missy!)

Alternate timelines
In an alternate timeline where the Cybermen allied with Rassilon to take over history, (COMIC; Supremacy of the Cybermen) the Master, while fighting the Third Doctor, was caught up in a time distortion which resulted in him being cyber-converted while pleading to the Doctor for help. (COMIC: Prologue: the Third Doctor)

Parallel universes
In the Inferno Earth, the Master was still a loyal Time Lord who went under the name Koschei. He was working for the Celestial Intervention Agency and travelled with a human companion called Ailla. They became stranded on Earth after defeating the Great Intelligence, and the Republic of Great Britain captured him for information. Ailla was killed and Koschei was tortured until all his regenerations were used up. Koschei died when he was confronted by the Master from N-Space, who turned off his life-support machine at his request. (PROSE: The Face of the Enemy)

In one universe where the Unbound Doctor was not UNIT's scientific advisor because his exile did not take place in the 1970s, the Master worked for the United Nations, until he defected to China, when his TARDIS was placed beyond his reach. He used alien parasites to brainwash political prisoners, making them mindless soldiers, later to be organised in the infamous Ke Le Divisions. In 1997, when the new Chinese government lost faith in him, the Master tried to escape to Hong Kong, allegedly defecting back to the West; he regenerated into a new incarnation after being caught in a plane crash during this attempt. (AUDIO: Sympathy for the Devil)

In an alternative universe created by the Quantum Archangel, the Master joined the Time Lords to fight in the War. However, he began aiding the Daleks by giving them temporal manipulation technology. The Sixth Doctor, who was Lord President Admiral of Gallifrey, activated the Armageddon Sapphire and destroyed the universe rather than letting the Enemy win. (PROSE: The Quantum Archangel)

In a different alternative universe created by the Archangel, the Master cooperated alongside the Rani, the Monk and Drax to try to destroy the world using a DNA recombinator, turning the human race into a gestalt consciousness which could be used as a weapon to conquer the universe. (PROSE: The Quantum Archangel)

Other references
Portrait of Evil was the only known painting in existence to depict the Master. Painted by Skarnn, it was exposed in the Church of the Evergreen Man's Oakdown Gallery on Piedosos. A human history of the Daleks included a reproduction of the painting as an illustration of the Master; the painting depicted him in the very incarnation (PROSE:  Dalek: The Astounding Untold History of the Greatest Enemies of the Universe) who had once allied himself with the Dalek Supreme Council. (TV: Frontier in Space)

Doomed Alliance was created by Alcide Esposito in 2544 and depicted four Grey Daleks, the Dalek Supreme, and a shadowy figure "believed" to be the Master. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

Joel Shaw acknowledged the Third Doctor's nemesis as the first of the Master's three known "regenerations", followed by and. (TV: Police 5: The Master)

As recorded in the Masterplan Journal left behind by, had carved the image of "Beardy One" into Mount Rushmore during the Year That Never Was along with his then current self,  and , observing that there was no room for. (PROSE: The Secret Diary of the Master)

Whilst trapped in the Matrix, the Thirteenth Doctor remembered, amongst many others, the Master in order to break out of the computer system. (TV: The Timeless Children, TV: The Sea Devils)

Behind the scenes

 * Barry Letts and Terrance Dicks often discussed that the relationship between the Third Doctor and the Brigadier was similar to Sherlock Holmes and Dr. Watson, and envisioned a counterpart of the Doctor to act as "Moriarty", a character that became "the Master", his name being developed to counter the Doctor's — like that of his enemy, "Master" is an academic title.(DOC: The Doctor's Moriarty)
 * In the Third Doctor's original final episode concept, Roger Delgado's incarnation of the Master would have redeemed himself and given his life to save the Doctor, after which the Doctor would have regenerated; however, this story was never developed due to the sudden death of Roger Delgado. Over thirty years later, this idea was reused in The End of Time, with John Simm's incarnation of the Master sacrificing himself to save the Tenth Doctor from Rassilon.
 * The 2020 animated version of the Second Doctor serial The Faceless Ones retroactively makes this story the Master's first appearance, though they do not appear in person. He appears on two separate wanted posters, one showing his Roger Delgado incarnation, and another showing played by Sacha Dhawan.