The Master


 * This article is about the renegade Time Lord known as "The Master." For other uses of the term "Master", see Master (disambiguation).

The Master, formerly known as Koschei and by various temporary aliases and pseudonyms, was an evil renegade Time Lord who had grown up with the Doctor on Gallifrey, and was opposed by him many times. On at least one occasion, he threatened the existence of the universe itself. A possible reason for his diabolical madness was a neverending drumming sound inside his head, revealed to be a link retroactively installed by the Time Lords on the last day of the Time War in order to further their own goals.

Childhood
Koschei, later known as the Master, grew up on Gallifrey, in the House of Oakdown. (PDA: Divided Loyalties) But he would later comment to Wilfred Mott that growing up on Gallifrey was not something that Wilf would call childhood, instead, "...more a life of... duty..." (DW: The End of Time)

He and his one-time friend the Doctor, in their youth, would play in the fields (presumably) near Koschei's home. He claims his father had estates, with "pastures of red grass", near "Mount Perdition". (DW: The End of Time)

The Master's true origins are surrounded in mystery and there are many conflicting theories about it. In his seventh incarnation, the Doctor related a story which explained the Master's origins. He said that both he and the Master had been mercilessly and viciously bullied as children. The young Doctor found himself forced to kill the bully in order to save his friend's life. He was later confronted by the personification of Death who insisted he become her disciple.

The Doctor refused and instead suggested Death make the Master her champion instead, to which she agreed. The Doctor said that ever since he had always felt partly responsible for the carnage the Master would later cause. (BFA: Master)


 * It's not clear whether this event (or its canonicity, as it is never referred to in the TV series) occurred before or after the event described below. 

Like most Gallifreyans taken as Time Lords, Koschei would be taken at the age of eight for his training. During the ceremony where he gazed into the Time Vortex through the Untempered Schism, it is said that Koschei went insane. This manifested by the constant drumming he heard ever since the event, which appeared to worsen as time went on. (DW: Utopia / The Sound of Drums / Last of the Time Lords) The drumming itself was later revealed to have been implanted retroactively into the Koschei's mind by Rassilon as a link to later free the Time Lords from the time-lock imposed upon them. (DW: The End of Time)

Youth
At the Academy, Koschei belonged to a clique of young Time Lords with the collective name of the Deca. The Doctor and other future rivals Ushas (later known as the Rani) and Magnus (later known as the War Chief) also belonged to the Deca. (PDA: Divided Loyalties)

Origins of the vendetta
After the Doctor fled Gallifrey, Koschei was recruited to pursue and apprehend him. His unstable obsession with order however, prompted the Time Lords to plant the Time Lady Ailla as a spy to monitor Koschei's actions. Ailla posed as a Human so that Koschei would take her on as his companion during a stopover in the 28th century. Koschei caught up with the Doctor at the Darkheart colony in the early years of the Federation.

The temptation posed by the Darkheart device proved too much for Koschei, and the revelation that Ailla had been a spy killed the last traces of good in him. After the Doctor trapped him in a black hole Koschei, the Master, swore to take revenge on him. (MA: The Dark Path)

The vendetta continues
The Master then sought to defeat the Doctor during the latter's exile on Earth. Because of the Doctor's affiliation with UNIT, the Master thus became a known enemy to authorities on Earth, and was even imprisoned for a short time by Human authorities.


 * For details on this period of his life, see separate article.

Terserus
The Master eventually came close to death, but was able to survive in a decaying body. In this body, he attempted to gain a new regenerative cycle using the Eye of Harmony, but was stopped by the Doctor. The Master escaped Gallifrey, and eventually arrived on Traken. He eventually possessed the body of a Trakenite named Tremas.
 * For details on this period of his life, see separate article.



Usurpation
The Master did manage to steal the body of Tremas, the father of the Doctor's future companion, Nyssa. (DW: The Keeper of Traken) He immediately set out on a new career of villainy in his new body. (DW: Logopolis) Eventually, he found himself taken over on the Cheetah World by a foreign influence and began to lose control. He ended up trapped there as it began to die. (DW: Survival)


 * For more details on this incarnation, see separate article.

New regenerative cycle
The Master was able to teleport from the Cheetah World to 1953 Earth where he constructed himself an identity as Major Kreer. He made a deal with the Tzun to restore his corrupted Time Lord DNA, caused by his physical merger with the Trakenite, Tremas. This was a success, and he was able to regenerate into a new body. (NA: First Frontier)

The Master later attempted to seize control of a powerful artifact known as the Warp Core. This plan backfired and due to his exposure to the device the Master's body reverted to a state similar to his degenerated form. For a while he persisted in trying to acquire the Core. During that time he habitually wore a mask and adopted the alias Mr Seta. (BFA: Dust Breeding)


 * From the perspective of the Doctor and Ace, this took place before, not after the Master's meeting with the Tzun.

Doctor John Smith
The Doctor related a story of how he made a deal with Death whereby the Master would have ten years of peace and sanity, at the end of which the Doctor must kill him. The still-scarred Master had become a physician with no memory of his past, and took the name Doctor John Smith.

He was still somehow deeply aware of his dark nature and troubled by it. The Master had, in the meantime, become emotionally involved with a woman named Jaqueline Schaeffer.

At the end of the ten years the Doctor duly arrived but strove to avoid fulfilling his side of the bargain. The Master became aware of the Doctor's role in pledging him to Death as her servant but forgave him for it. Death herself was present then, disguised as the Master's maid. She manipulated events so that it would appear inevitable that the John Smith persona would crumble and the true Master become dominant once more. (BFA: Master)



Death and life again
Eventually, he was tried and executed and physically destroyed by the Daleks on Skaro as part of a Time Lord-Dalek treaty. However, his essence survived in a fluid-like form called either a morphant (DWM: The Fallen) or a deathworm (EDA: The Eight Doctors). His "last wish" was for the Doctor to transport his remains to Gallifrey; during transport, the Master was able to sabotage the Doctor's TARDIS, forcing it to land on Earth in 1999. The Master subsequently took over the body of Bruce, an ambulance driver in San Francisco. This incarnation was only intended to be a temporary one -- indeed, "Bruce" began to decay almost immediately -- as the Master launched a scheme to steal the Doctor's remaining regenerations. At the end of a battle with the recently regenerated Doctor himself, the Master fell into the Eye of Harmony, and appeared to be destroyed. (DW: Doctor Who)


 * For more on this incarnation, see separate article.

The Eye of Harmony spat the Master into the Vortex where he was rescued by a being named Esterath, the then-controller of the Glory, the focal point of reality. It would soon be time for the Glory to gain another controller, but the power had to be fought for. Of course, the Master assumed the battle would be between himself and his greatest foe. Given a new body, the Master trailed the Doctor for some time without his enemy suspecting - even after they had met face to face. He was present in London during the crisis resulting from Grace Holloway's attempt to merge Human and Time Lord DNA (the alien DNA was in fact that of a morphant from Skaro). He killed an MI6 agent with the TCE at this time, but fortunately the Doctor departed before the Master's trademark was discovered. (DWM: The Fallen)

The Master later made contact with Sato Katsura, a Japanese samurai unwillingly rendered immortal as a result of his involvement in the Doctor's adventures. The embittered warrior became the Master's follower. At his behest, Sato adopted the identity of Cardinal Morningstar and became leader of the Church of the Glorious Dead, instigator of a holy war that altered the history of Earth and led to it becoming known as Dhakan.

Passing through the Eye had given the Master the ability to influence the flight of the TARDIS, which he used to send the craft to times and places which would weaken the Doctor's self-belief and confidence. This done, the two fought for the Glory, with the Master apparently triumphant.

However, the Master was mistaken: the true battle was between his companion, Sato, and the Doctor's, the Cyberman Kroton. Kroton was the ultimate winner of this contest, and amongst his first acts as controller of the Glory were to cleanse the TARDIS of the Master's influence, and to banish the Master to parts unknown. While being banished, the Master declared he would survive and return. (DWM: The Glorious Dead)

The Master escaped from the Eye of Harmony after influencing the dreams of Edward Grainger, the Master was now just a being of energy that could travel through the air. After escaping from the TARDIS, he managed to evade the Doctor's detection on Earth and possessed the body of a Human native in 1906. (ST: Forgotten)

During the Second War in Heaven, President Romana was moved to a duplicate of Gallifrey. The Master then returned to Gallifrey and warned the Time Lords that he had been captured and interrogated about his world by the agents of the Enemy. The Master was given the total amnesty for his crimes, and became the War King of the Homeworld. (FP: The Book of the War) He led the Time Lords against the Enemy, made peace with the Osirians and even created a pact with Compassion to create a second front against the Enemy. He was later "eaten" by Lolita during her betrayal and later allied herself with Sutekh against him and Gallifrey. (MB: Words From Nine Divinities) The Master was cloned during the conflict, the clone was killed by Father Kreiner who kept his head as a trophy. (EDA: Interference: Book One)

Due to the Doctor erasing many events of the War before they occured, many of the events depicted here never actually happened. (EDA: The Ancestor Cell)

The Master survived the War and Gallifrey's destruction, he then visited the Doctor on Earth during the late 18th Century. While he was there he attended the Doctor's wedding and attempted to explain the Doctor's past to him and the fate of the Time Lords, the Doctor was suffering from amnesia at the time but still knew who the Master was. (EDA: The Adventuress of Henrietta Street)

Return
In the Last Great Time War, the Time Lords themselves brought the Master back from oblivion in order to use him as a weapon in defence of Gallifrey. However, he deserted the instant the Dalek Emperor took control of the Cruciform (DW: The Sound of Drums) as the sheer scale of the conflict seemed to frighten even the Master. He fled to the end of the universe and used a Chameleon Arch to become Human, remaining in the guise of the elderly Professor Yana. Martha Jones, who had traveled to this time period with the Doctor, recognized Yana's fob watch as similar to or the same as the one carried by the Doctor after he experienced the Chameleon Arch and unintentionally prompted Yana to open the watch. The Master returned in his old identity and attacked his assistant, killing her even as she shot him in the stomach. (DW: Utopia)


 * For more information on Yana, see separate article.

Fatally wounded, though now aware of his identity, the Master regenerated (in one of the few confirmed accounts from his later life of him actually undergoing a natural regeneration) and escaped to 2000s Earth in the Doctor's TARDIS. (DW: Utopia) There he assumed the identity of Harold Saxon a name spotted on many political posters around England (Love and Monsters, Smith and Jones,The Lazarus Experiment,The Sound of Drums) and successfully ran for the position of Prime Minister. He then proceeded to take the Doctor prisoner and take over the Earth with the help of the Toclafane and a paradox machine he had made from the TARDIS. This timeline was reverted, however, when Jack Harkness destroyed the paradox machine. As the Doctor took him into custody, the Master was shot by Lucy Saxon, and collapsed in the Doctor's arms. Knowing that he and the Doctor were the last two remaining Time Lords, and knowing how badly the Doctor wanted to not be alone, he refused to regenerate, telling the Doctor, "I win." The Doctor burned his body on a funeral pyre, but a mysterious figure retrieved the Master's ring from the ashes.(DW: The Sound of Drums/Last of the Time Lords)


 * For more details on this incarnation see Harold Saxon. See The Year That Never Was for details of the timeline in which he ruled Earth.

Resurrection and redemption
The Master was resurrected by the Disciples of Saxon, a sinister cult who worshipped the Master. Lucy Saxon, however, had made a potion of death to counter the potion of life used to revive the Master. In the ensuing explosion, the Master escaped as a shadow. Once he regained physical form, he discovered that the interruption of the ritual had left bizarre side-effect. He was pale and ghost-like and even dyed his hair white-blonde in an attempt to be unrecognisable as Harold Saxon. His flesh would occasionally turn transparent, exposing his skull. In addition he had developed the ability to shoot bolts of artron energy from his hands and the power of flight, but using these abilities came at the cost of his life-force. Furthermore, he seemed more insane than ever. His previously urbane and sophisticated personality had been replaced with a frenzied bloodlust and a ravenous and insatiable hunger. He would kill everyone he encountered for little to no reason, laughed maniacally at the slightest occurrence and his behaviour bordered on that of a wild animal.

The Doctor found the Master and pursued him. They confronted one other and the Master used his psychic Time Lord abilities to let the Doctor into his mind, letting him hear the drums. The Doctor seemed profoundly disturbed and the Master escaped again. The Doctor still pursued him until the Master was kidnapped and taken away.

He was told to fix an alien gate called the Immortality Gate. The Master obviously jumped at the opportunity and fixed it. The Doctor and Wilfred Mott came into the room just as The Master entered the gate and Wilfred hid in an anti-radioactivity chamber of the power supply. The gate is found out to be a machine that changes the genetic DNA of the whole planet changing all Humans into his image. Everyone looked alike and acted alike. Only two humans escaped, Wilfred Mott, who was safe in the chamber, and Donna Noble, who was safe because she was part Time Lord.

The Master later realised that the Time Lords were returning through the discovery of a Gallifreyan diamond, sent through the time lock by Lord President Rassilon, and also learned that the drumbeat in his head was a link that the Time Lords could use to return to the material universe. Upon their arrival, the Time Lords undid his actions with the Immortality Gate, restoring the human race. The Master soon learned that Rassilon had placed the noise of drums in his head as a child to be used as a link to Earth. As Gallifrey appeared in Earth's sky on a collision course with Earth, the Doctor had to decide between killing the Master and killing Rassilon. If the Doctor killed the Master the link would be broken and everything would return to normal, but if he killed Rassilon, the Master indicated the Doctor would become the new leader of the Time Lords as Rassilon is Lord President. After the Doctor notices The Woman, he turns on the Master to apparently kill him, but instead orders him to "get out of the way." The Master, realizing what he intends, dives to the side as the Doctor destroys the Whitepoint star with a shot from Wilfred Mott's gun, severing the link as the diamond was acting as an anchor. As Rassilon prepared to kill the Doctor, the Master, in an act of vengeful and possibly heroic self-sacrifice, used the last of his life-force to disable the deranged Time Lord leader before both the Time Lords and the Master vanished in a burst of white light. His final action saved the Doctor, and helped save the universe by stopping the Time Lords' plans, returning them and Gallifrey to the Time War. It is currently unknown if and how the Master survived. It is likely he was sucked back into the Time War with the other Time Lords and died when the Doctor destroyed Galifrey. (DW: The End of Time)

Schemes

 * The Master comes to Earth in order to help the Nestene Conciousness and the Autons conquer the world. (DW: Terror of the Autons)
 * The Master uses the KELLER MACHINE to startle a peace conference and create World War Three. (DW: The Mind of Evil)
 * The Master uses the alien parasite (AXOS) to drain the Earth of all of its energy. (DW: The Claws of Axos)
 * The Master poses as an adjudicator to find a deadly doomsday weapon. (DW: Colony in Space)
 * The Master disguises himself in order to strike a deal with the ancient daemon, Azal. (DW: The Dæmons)
 * The Master escapes his prison to help the Sea Devils reclaim their land (Earth). (DW: The Sea Devils)
 * The Master harnesses enough power to destroy the entire city of Atlantis. (DW: The Time Monster)
 * The Master uses Ogrons to incite conflict between Earth and Draconia, on behalf of the Daleks. (DW: Frontier in Space)
 * A dying Master returns to Gallifrey and frames the Doctor for assassinating the High President. (DW: The Deadly Assassin)
 * The Master becomes the great keeper of Traken/he gets a new body. (DW: The Keeper of Traken)
 * The new Master attempts to destroy the universe by using the secret of Logopolis. (DW: Logopolis)
 * The Master uses the city of Castrovalva to trap the newly regenerated Doctor. (DW: Castrovalva)
 * The Master brings an air-craft back to prehistoric Earth/He takes control of the Xeraphin. (DW: Time-Flight)
 * The Master uses the robot, Kamelion, to replace King John and prevent the creation of the Magna Charta. (DW: The King's Demons)
 * The Master is sent into the Death Zone to rescue the first five incarnations of the Doctor. (DW: The Five Doctors)
 * A miniaturized Master uses Kamelion to regain his full size once again. (DW: Planet of Fire)
 * The Master helps the Rani to stop the Doctor in the 19th Century. (DW: The Mark of the Rani)
 * The Master watches the Doctor on trial and attempts to help the Valeyard stop the Doctor. (DW: The Trial of a Time Lord)
 * The Master is trapped on an alien world and must uses cheetah people to stop his mutation. (DW: Survival)
 * The Master uses the Eye of Harmony to destroy the Doctor in San Francisco, 1999. (DW: Doctor Who)
 * The Master returns and uses a Paradox Machine to resurrect the Human Race on Malcassairo in the year 100 trillion to destroy 10% of Earth's population and create a Time Lord Empire on Earth. (DW: The Sound of Drums/Last of the Time Lords)
 * The Master returns and creates the Master Race to bring back the Time Lords. (DW: The End of Time)

Companions
Unlike the Doctor, the Master was most often encountered working and traveling alone. On rare occasions, he was seen with companions. Examples included Chang Lee, a young Human whom the Master met in San Francisco (DW: Doctor Who); Katsura Sato, an immortal Japanese Samurai who helped the Master in his quest for Glory; Chantho, a female assistant and companion to the Master during his Professor Yana identity (although both of them were unaware of "Yana"'s true nature for most of that time) (DW: Utopia); and Lucy Saxon, his wife, who was described as having traveled with the Master in the TARDIS in the same fashion as the Doctor and his companions. (DW: The Sound of Drums/Last of the Time Lords) The Rani may have also traveled with the Master for a time, when they got trapped together. (DW: The Mark of the Rani)

Imitators
The Master has at least one (rather pathetic) imitator. This is in the form of the Mentor. (DWM: Death to the Doctor!)

Other versions of the Master

 * Following graduation from the Time Lord Academy, the Master, using the name Koschei, pursued a career as Magistrate for the High Council. In this capacity, his devotion to justice and discipline in time devolved into an obsession with order which marked the beginning of his descent into darkness (PDA: The Infinity Doctors)
 * We do not know if this event occurred before the Master had left Gallifrey, in an alternative timeline or after he had reformed and returned to Gallifrey.


 * While helping UNIT stop an invasion by a parallel Earth, the Master met that alternate reality's version of himself, still using the name Koschei, imprisoned and vivisected by order of that reality's version of the Doctor. The Master killed his other self, claiming this was an act of mercy. (PDA: The Face of the Enemy)
 * In an apparent alternate timeline, a version of the Master exists as an android companion to the Doctor. (WC: Scream of the Shalka)
 * In the reality created around Donna, it can be assumed that as a result of the Doctor and Martha Jones' deaths, the Master never found out who he really was and never travelled back to Earth, as the Doctor never lived to discover him on Malcassairo. Presumably "Professor Yana" continued working with Chantho to preserve remainder of the human race (DW: Turn Left)

Personality
The Master was the polar opposite of the Doctor in almost every respect. Though he retains a brilliant Time Lord mind and all of the Doctor's wit and cunning, he possesses two fatal character flaws - he was arrogant and exceptionally vain, which leads to his downfall on many occasions. By the time of his return from his Yana persona, he appeared after his regeneration to have gone more insane than ever, regressing to an almost childlike state of spitefulness and obliviousness. It is implied by the Doctor that the Master's insanity has been present ever since he was eight years old. He instantaneously rejected a plea to listen by saying, "No. It's my turn. Revenge." (DW: Last of the Time Lords)

In this instance, the Doctor, being aware of how dangerous the Master was, attempted to take on the role of a kind of mentor in an attempt to save the Master from himself "I'm not here to kill him. I'm here to save him". He pleads with him on numerous occasions (DW: Utopia, The Sound of Drums, Last of the Time Lords) to calm down, stop what he is doing, listen and look at himself.

The Master absolutely refused to listen to the Doctor on either occasion. He revealed his vanity when the Doctor confronts him with the words "I forgive you", which he had been terrified of hearing because it would have significantly dented his pride. (DW: Last of the Time Lords)

He also had an exceptionally heightened sense of his own brilliance which is far more pronounced and blatant than that of the Doctor. He refers to himself in the third person as "your Lord and Master" on numerous occasions and in reciting a Bible-style verse of his own making to the Doctor, "...and so it came to pass that the Human race fell. And I looked down, upon my new dominion as Master of All and I thought it good", reveals a penchant for fancying himself as a god. (DW: The Sound of Drums) He also holds Time Lords to be an absolutely superior race of life automatically assuming the privilege of altering history, on principle of this: "I'm a Time Lord. I have that right" (DW: Last of the Time Lords). Similarly, in a late Tenth Doctor story, DW: The Waters of Mars, the Doctor was seen to shout "The laws of time are mine, and they will obey me!", which Russell T Davies later stated was influenced by how he thinks The Master came to be how he is. The Doctor later realises that he has gone too far and most likely recognises the parallels between his actions and the Master.



In some of his incarnations he felt the strange need to correct people on bad grammar. Most notable scenes of this are in the TV Movie, where he corrects Grace from saying "kiss as good as me" to "kiss as well as me". Also in a commentary podcast for DW: The End of Time, Russell T Davies said that in an original version of the script the Master corrected someone from saying "Happy Christmas" to "Merry Christmas" telling them "you don't say merry new year, do you?"

He was able to match the Doctor's keen wit and sense of humour, particularly the Master's sixth incarnation. He remarks to the President of the United States when reprimanded for his audacious conduct contravening established first contact policy with regards to the Toclafane with a casual "Oh, you know what it's like, new job, all that paperwork … I think I left it down the back of the settee. I did have a quick look … I found a pen, a sweet, a bus ticket … have you met the wife?" (DW: The Sound of Drums)

The Master also shared the Doctor's incredible technical know-how. He was able to construct his laser screwdriver from Earth components and miniaturise Richard Lazarus' genetic manipulation technology. He was also able to cannibalise the Doctor's TARDIS and turn it into the Paradox Machine

It should also be noted that both devices, in contrast to the Doctor's tools, had a hostile purpose; the laser screwdriver is a weapon specifically created to offensively attack and kill others, unlike the Sonic Screwdriver which "doesn't kill, wound, or maim". (DW: Doomsday)

The Master also had a crippling fear of an all-powerful, God-like Doctor probably based around the Doctor's habit of challenging his old foe's grandiose self-image by constantly derailing his plans. (DW: The Mind of Evil) When the Doctor harnessed the psychic energy of the entire human race and effectively became a god, the Master was reduced to sobbing against a wall. (DW: Last of the Time Lords)

The Master's relationship with the Doctor is one of the most complex in the series. He respects him as a worthy opponent but was also obsessed with proving his personal superiority, causing him to view the Doctor both as his greatest friend and his worst enemy. He expressed deep anger toward the Doctor, along with a desire for vengeance, saying "No, it's my turn, revenge, best served hot". (DW: Last of the Time Lords)

It's also revealed that the Master hadn't always been like this however: he and the Doctor were once good friends as children on Galllifrey, but the Doctor thinks that staring into the Time Vortex as an eight-year old child drove him insane and caused his personality to change. (DW: The Sound of Drums)

After the Master's revival, he was more insane than ever before. He acted like an animal, eating food like one and acting rash. He could be close to sane when talking to the Doctor and was sure he was not insane when the Doctor finally heard the drums he hated so much. At the very end of his life, his personality seemed to revert as when Rassilon tried to kill the Doctor he sacrificed himself as he found a common enemy between him and the doctor (Rassilon), to use an unknown amount of his life-force to blast Rassilon and save the Doctor when he could have let Rassilon kill the Doctor and survive himself. (DW: The End of Time)

Name
The name "Koschei" has been developed in various novels and other media, and is therefore of questionable canonicity in regards to the TV series like all Doctor Who spin-off material. Like the Doctor the Master's real name has yet to be revealed on-screen.

Koschei (rus.Кощей) is the villain in many antique Russian fairytales. He is an immortal magician who hides his death in a secret place.

Conception and development of the character
When conceiving the character, the production team had originally considered the idea of the Doctor having a female, rather than male, arch-nemesis (this idea was later revived with the creation of the Rani). Later, they thought of the Master as the evil half of a single personality.

In the final Third Doctor episode, the Master would have redeemed himself and given his life to have saved the Doctor, after which the Doctor would have regenerated. The accidental death of Roger Delgado, who had played the original version of the Master made it so that this development never happened. This idea would eventually be reused in The End of Time, in which the Master sacrificed himself to save the Doctor from Rassilon.

In The Deadly Assassin, writer (and then Script Editor) Robert Holmes deliberately chose to show the Master in a "transitional" form in case future production teams wanted to bring back the character.

Actors who have portrayed the Master

 * Apart from the incarnations below, other incarnations of the Master have appeared in novels and comics.

Television appearances (1971-1989)

 * Roger Delgado as the first version of the character to appear on Doctor Who. He first appeared in the role in 1971's Terror of the Autons.
 * Peter Pratt and Geoffrey Beevers as his next incarnation (both actors played the same incarnation of the character). They appeared in The Deadly Assassin and The Keeper of Traken, respectively.
 * Anthony Ainley as The Master in the body of Tremas from the last moments of The Keeper of Traken through the last original series story Survival, making him the longest running actor to portray the Master up to the present day. Note that the character had several extended absences from the series.

TV Movie and mini-episode (1996 and 1999)

 * Eric Roberts played the Master in the body of Bruce, in Doctor Who.
 * In the same production, Gordon Tipple appeared in a non-speaking role as the Master's previous incarnation.
 * Jonathan Pryce played "The 17th Master" in a non-canonical spoof mini-episode, The Curse of Fatal Death.

New series (2007)

 * Derek Jacobi played Professor Yana, a Human version of the Master, as well as the Master himself once he was reverted back to a Time Lord.
 * John Simm played the Master's next incarnation, initially taking the name Harold Saxon. Both Jacobi and Simm debuted as the Master in Utopia, though only Simm appeared in the following episodes The Sound of Drums and Last of the Time Lords. He returned in The End of Time, during which the character renounced the Saxon name and chose to be called, simply, the Master.
 * William Hughes had a non-speaking cameo as the young Master during a flashback sequence in The Sound of Drums which was later reused in The End of Time.

Animation

 * Derek Jacobi also played another incarnation of the Master in the web-based animation Scream of the Shalka.

Audio

 * Geoffrey Beevers reprised the role in the audio plays Dust Breeding and Master.
 * Mark Gatiss played an alternative version of the character in Sympathy for the Devil.

Video game

 * Anthony Ainley reprised the role in videotaped scenes included in the game Destiny of the Doctors. These sequences appear as extras on the DVD version of Survival, his last television story.

Continuity

 * The Doctor Who Role Playing Game from the American gaming company FASA identified the Monk and the War Chief as earlier incarnations of the Master, causing a few fans to mistakenly believe that Doctor Who itself had stated a connection, when it had not done so. Novel and comic continuity specifically indicates otherwise.
 * The Big Finish Productions audio play Master and the television episode The Sound of Drums have the Doctor telling two different and apparently contradictory explanations for how the Master turned evil (Although it may be that both the schism and the deal with Death were responsible, with the deal with Death making the Master's madness more powerful).
 * Although novels have been written establishing the "first" Master's activities between the final televised appearance of Roger Delgado Frontier in Space and the character's return in The Deadly Assassin in a degenerated form, the latter adventure makes no direct link. Therefore it can't be said for certain (based upon on-screen evidence) whether this incarnation is the same one played by Delgado.

Anagrams
During Anthony Ainley's tenure as the Master, pseudonyms made from anagrams of the actor's name were often used in the credits for the Master's disguises, such as Neil Toynay for the Portreeve in DW: Castrovalva. Tremas is itself an anagram of Master.

At the same time, in Series 3 (season 29), the Master takes on two new identities, Professor Yana in DW: Utopia, and Mr. Harold Saxon in DW: The Sound of Drums and DW: Last of the Time Lords. As it happens, "Mister Saxon" is a possible, albeit an unintentional anagram of "Master No. Six" as "Sam Tyler" (John Simm's Life on Mars character) is an anagram of "masterly". Yana is an intentional acronym of 'You Are Not Alone', the final words of the Face of Boe, which led the Doctor to discover Yana was a Time Lord.