When the Master first appeared in 1971 he was played by Roger Delgado, who continued in the role until his death in 1973. Afterwards, Peter Pratt and Geoffrey Beevers played a physically decayed version of the Time Lord, until Anthony Ainley assumed the part in 1981. He remained until Doctor Who's cancellation in 1989. In 1996, the Master was played by Gordon Tipple(briefly) and Eric Roberts in the TV movie. In the revived series, Derek Jacobi briefly provided the character's re-introduction, before handing over to John Simm, who portrayed the Master in the climax of the 2007 series.
The creative team conceived the Master as a recurring villain, a "Professor Moriarty to the Doctor's Sherlock Holmes." He first appeared in Terror of the Autons (1971). The Master's title was deliberately chosen by producer Barry Letts and script editor Terrance Dicks as evocative of supervillain names in fiction, but primarily because, like the Doctor, it was a title conferred by an academic degree.
Barry Letts had one man in mind for the role: Roger Delgado. Delgado had a long history of screen villainy and had already made three attempts to break into the series. He had worked previously with Barry Letts and was also a good friend of Jon Pertwee.
In "The Sound of Drums" (2007), a flashback shows the Master at the age of eight, when as part of a Time Lord initiation ceremony he is taken before a gap in space and time known as the Untempered Schism, from which one can see the entire Vortex. The Doctor states that looking into the time vortex causes some to be inspired, some to run away, and others to go mad; he suggests that the last is what happened to the Master.
A would-be universal conqueror, the Master's stated goal is to control the universe (in The Deadly Assassin his ambitions were described as becoming "the master of all matter", and in "The Sound of Drums" he acknowledges that he chose the name "the Master"), with a secondary objective of eliminating the Doctor. His most distinctive ability is that of hypnotising people by fixing them with an intense stare, often accompanied by the phrase, "I am the Master, and you will obey me." The original (and most common before 1996) look of the character was similar to that of the classic Svengali character; a black Nehru outfit with a beard and moustache. A favoured weapon of the Master is his Tissue Compression Eliminator, which reduces its targets to doll-size, usually killing them in the process.
In his three seasons beginning with Terror of the Autons, the Master (as played by Delgado) appeared in eight out of the fifteen serials. Indeed, in his first season the Master is involved in every adventure of the Doctor's, always getting away at the last minute before he is captured in The Dæmons (1971), only to escape imprisonment in The Sea Devils (1972). He would often use disguises and brainwashing to operate in normal society, while setting up his plans; he also tried to use other alien races and powers as his means to conquest, such as the Autons and the Daemons. Delgado's portrayal of the Master was as a suave, charming and somewhat sociopathic individual, able to be polite and murderous at almost the same time.
Delgado's last on-screen appearance as the Master was in Frontier in Space, where he is working alongside the Daleks and the Ogrons to provoke a war between the Human and Draconian Empires. His final scene ended with him shooting the Doctor and then disappearing. Delgado wanted the Master to make one more appearance, in a story titled The Final Game (also planned as the Third Doctor's last story), in which the character would be killed off, with an ambiguity as to whether he had in fact died to save the Doctor. However, Delgado was killed in a car accident in Turkey on June 18, 1973, while on his way to shoot footage for the French comedy The Bell of Tibet. The next Master story was replaced by Planet of the Spiders (1974).
With Delgado's death, the Master disappeared from the series for several years. In his next appearance, in The Deadly Assassin (1976), the Master (played by Peter Pratt under heavy make-up) appears as an emaciated, decaying wreck, at the end of his thirteenth and final life. Given the severity of his situation, this Master is much darker than Delgado's version. After this story, the Master again departs the series, returning in 1981. In The Keeper of Traken, the Master (Geoffrey Beevers under different heavy make-up but playing the same incarnation as Pratt) succeeds in renewing himself by taking over the body of the Trakenite Tremas (an anagram of "Master"), overwriting Tremas's mind in the process. Now played by Anthony Ainley, the Master appeared on and off for the rest of the series, still seeking to extend his life — preferably with a new set of regenerations. In his first appearance in Logopolis, his scheme to kill the Doctor and gain control over Logopolis accidentally leads to advanced entropy destroying a large part of the known universe (including Traken).
In many of his appearances opposite the Fifth Doctor, the Master shows his penchant for disguise once again, on one occasion operating under concealment for no clear plot reason. The character's association with playful pseudonyms also continued both within the series and in its publicity: when the production team wished to hide the Master's involvement in a story, they credited the character under an anagrammatic alias such as "Neil Toynay" (Tony Ainley) or "James Stoker" (Master's Joke).
Ainley's final appearance in the role, in Survival, was more restrained. He was also given a more downbeat costume, reminiscent of the suits and ties worn by Delgado's Master. In this final story, he had been trapped on the planet of the Cheetah People and been affected by its influence, which drove its victims to savagery. Escaping the doomed planet, he attempted to kill the Doctor, a plan which left him trapped back on the planet as it was destroyed.
The Master also appeared in the 1996 Doctor Who television movie that starred Paul McGann as the Eighth Doctor. In the prologue, the Master (seen briefly, portrayed by Gordon Tipple) was executed by the Daleks as a punishment for his "evil crimes". It is not known whether Tipple was portraying the same incarnation of the Master as Ainley did. Most novelisations and comics published around the same time as the release of the movie are written from the perspective that it is Ainley's Master, but the movie leaves the question open.
The Master survives his execution by taking on the form of a small, snake-like entity. This entity escapes and slithers inside the Doctor's TARDIS console, forcing the vessel to crash land in San Francisco.
The novelisation of the television movie by Gary Russell posits that the modifications and alterations that the Master has made to his body over the years in attempts to extend his lifespan had allowed this continued existence, and the implication is that the "morphant" creature is actually another lifeform that the Master's consciousness possesses. This interpretation is made explicit in the first of the Eighth Doctor Adventures novels, The Eight Doctors by Terrance Dicks, and also used in the Doctor Who Magazine comic strip story The Fallen (DWM #273-#276), which states that the morphant was a shape-shifting animal native to Skaro.
The morphant form is unsustainable and requires a human host, and it possesses the body of Bruce, a paramedic (played by Eric Roberts). However, Bruce's body is also unsustainable and begins to slowly degenerate, although he has the added ability to spit an acid-like bile as a weapon. The Master attempts to access the Eye of Harmony to steal the Doctor's remaining regenerations, but instead is bodily sucked into it.
Upon acquiring his new body, the Master dons a leather trenchcoat and aviator glasses (although he later swaps them for ceremonial Time Lord robes).
When Doctor Who was revived in 2005, it was initially claimed in the episode "Dalek" that all the Time Lords except the Doctor were killed in a Time War with the Daleks. The Doctor stated that if other Time Lords had survived, he would have been able to sense them telepathically. However the Master's return is foreshadowed in "Gridlock", when the Face of Boe gives the Tenth Doctor a message before dying: "You are not alone."
In "The Sound of Drums", it is revealed that the Time Lords resurrected the Master to serve as a front line soldier in the Time War. However, after the Dalek Emperor took control of "The Cruciform", he fled the war in fear and is ignorant of its outcome. He disguised himself as a human via the same process the Doctor himself used in "Human Nature" — a Chameleon Arch that stores his Time Lord nature and memories in a fob watch and allows him to become biologically human — and hid at the end of the universe as benevolent scientist, Professor Yana (portrayed by Sir Derek Jacobi). The Doctor meets this human incarnation in "Utopia", and Martha Jones inadvertently causes Yana to focus on the "broken" fob watch that contains his Time Lord essence, which calls on him to open it, using the voice and sounds of his former selves. He opens the watch and becomes the Master again, in a scene that makes clear that YANA is an acronym for the Face of Boe's last words (see above). He is mortally wounded during a struggle, regenerating into a new incarnation portrayed by John Simm. The Master then steals the Doctor's TARDIS and escapes, though, at the last second, the Doctor configures the TARDIS using his sonic screwdriver so that the Master is only able to travel between present-day Earth and the year 100 Trillion.
Third Doctor: Terror of the Autons • The Mind of Evil • The Claws of Axos • Colony in Space • The Dæmons • The Sea Devils • The Time Monster • Frontier in Space
Fourth Doctor: The Deadly Assassin • The Keeper of Traken • Logopolis
Fifth Doctor: Castrovalva • Time-Flight • The King's Demons • The Five Doctors • Planet of Fire
Sixth Doctor: The Mark of the Rani • The Trial of a Time Lord: The Ultimate Foe
Seventh Doctor: Survival
Eighth Doctor: Doctor Who
Tenth Doctor: "Utopia" / "The Sound of Drums" / "Last of the Time Lords"