War Master

The perfect warrior for the Last Great Time War, the War Master initially tried to manipulate the conflict to suit his own goals. However, after his failure to properly use the Heavenly Paradigm, this incarnation of the Master was driven to such a state of terror that he fled to the end of the universe and turned himself into a human baby with a chameleon arch to escape the Time Lords and wait out the conflict.

After spending many years living as a humble human scientist on Malcassairo, the Master's personality was reawakened by Martha Jones, and he made to steal the Doctor's TARDIS from the Tenth Doctor, but was fatally shot by Chantho, the Malmooth assistant to his human persona, and forced to regenerate into.

A day to come
The "Saxon" Master recounted to the Tenth Doctor that he had been resurrected by the Time Lords to fight in the Time War, as they foresaw he would be the "perfect warrior" for such a conflict. (TV: The Sound of Drums) There was historical doubt about how the Master had been resurrected and from which death, with the temporal nature of the Time War and its commonly rewritten events making it even more difficult to understand. (PROSE: A Brief History of Time Lords) One account suggesting that the Master had actually been extracted by the Time Lords from the Doctor's TARDIS, (PROSE: Doctor Who and the Time War) which lined up with having fallen into the Eye of Harmony as a result of his failed attempt to steal the newly regenerated Eighth Doctor's body. (TV: Doctor Who) Other accounts showed that the Master managed to escape the TARDIS but was eventually stripped of Bruce's body, reducing him back to who met his end at the hands of the Ravenous, still some time before the War, only to be resurrected and granted a new life cycle by an assembly of the Master's other incarnations, enabling him to regenerate into. (AUDIO: Day of the Master)

At some point, after dying for the sixteenth time, (PROSE: Girl Power!) the Master regenerated into a new incarnation. (PROSE: Girl Power!) This incarnation was then present in events before (AUDIO: Sins of the Father) and during the early phases of the Time War. (AUDIO: The Devil You Know) At some point, the Master designed a laser screwdriver for his own personal use. (AUDIO: The Heavenly Paradigm)

Scheming on Callous
The Master was employed by Narvin to go to the planet Callous to find the rare metal Swenyo. The Master went to Callous and began manipulating Elliot King, and eventually his daughter Cassandra, to mine the Swenyo. Eventually, due to his extreme guilt and the effects of the Swenyo, Elliot committed suicide. (AUDIO: Call for the Dead) Cassandra King and her wife, Martine King, went to Callous to rebirth the mining process, with aid from Ood miners and the Master in disguise. Due to the Master's aid, the mining process was a success, and Cassandra found an extremely concentrated amount of Swenyo, which the Master managed to acquire for himself by contacting the Teremon, the people that the King family worked for. (AUDIO: The Glittering Prize)

With Martine, the Master took the Swenyo to an asteroid, but Martine was driven mad by the physic properties of the Swenyo, and jumped off the asteroid to her death. (AUDIO: The Persistence of Dreams) After being captured by the Teremon, the Master escaped and weaponized the Ood to prevent the further mining of Swenyo. The Master then collected his Swenyo and gave it to Narvin, who gave the Master a Chameleon Arch in exchange. (AUDIO: Sins of the Father)

Escaping the Cybermen
While "exploring possibilities", the Master became stranded in a parallel dimension; when this dimension was invaded by the Cybermen of the Cyber-Mainframe, who originated from an alternate universe and sought to upgrade the multiverse, the Master used the opportunity to obtain Cyber-Technology to repair his TARDIS and followed the Cybermen back into N-Space. The Master landed his TARDIS, urgently in need of repairs, on Fortress Island on Earth during the 2010s, where the Cybermen, who had begun an invasion of Earth, attempted to cyber-convert him and Kate Stewart, but the two escaped with Josh Carter.

With his TARDIS stolen by the Cybermen, the Master reluctantly collaborated with Kate, Josh, Vikram Shindi and Sam Bishop. After he killed the Auctioneers, whose technology had enabled the Cyber invasion, they returned to Fortress Island. At the base, the Master was seemingly converted into the "Cyber-Master" by the virtually-converted Osgood, although this granted him the opportunity to destroy the Cybermen by expanding their dimension gate to draw power from all the parallel Earths the Cybermen had failed to commence full dimension seeding in. After removing his upgrades, the Master used the remaining contaminated energy to return in his TARDIS to "the fray" of the Time War, (AUDIO: Master of Worlds) leaving behind a Wirrn egg as a parting gift to UNIT. (AUDIO: Hosts of the Wirrn)

Escapades in the Time War
During the Time War, the Master fought the Supreme Dalek on the slopes of the Never Vault, (TV: The Witch's Familiar) and considered it a worthy opponent, even showing disappointment when the Dalek Emperor didn't send it to locate him on Arcking. (AUDIO: The Good Master)

On the Time Lords' orders, the Master spent years creating the ultimate biological weapon. He set up a facility on Xenotopia and personally recruited scientists. (AUDIO: Darkness and Light) His first subject was Alice Pritchard, a chronopsycho who had been adopted on Earth. (AUDIO: The Survivor) He next captured Giuseppe Sabatani from 1890s America. (AUDIO: The Coney Island Chameleon) He implanted a crew member of River Song's expedition on the Utorpy with an ancient alien egg, with the cooperation of her partner. As it reached gestation, the Master picked off the crew however River prevented him obtaining control of the creature and set the ship to self-destruct. Together they escaped in an escape pod and upon crashing, the Master hypnotised her to forget he'd been there. (AUDIO: Concealed Weapon)

For the final element, the Master lured the Doctor by tricking Alice into summoning him telepathically. Alice inadvertently drained the Doctor psychically, leading to him collapsing whilst he confronted the Master. He killed Alice, having served her purpose. The Master had tissue extracted from the Doctor (AUDIO: The Missing Link) and implanted a device in his head. The Master's work culminated in the creation of the Rage; the ultimate biological weapon. A CIA agent implanted within the Master's staff attempted to seize the creature, accidentally unleashing it in the process. The Master arranged the Doctor's escape, believing he would be able to tame with the creature. The Rage pursued and eventually absorbed them both, with the Doctor proving insufficient to tame it. Together the Doctor and the Master were able to overwhelm the creature, resulting in it perishing and releasing them both. The Master fled, using the device in the Doctor's head to wipe his memories of their encounter. (AUDIO: Darkness and Light)

Responding to a distress call from his secret base, the Master encountered Liv Chenka, posing as a Time Lord agent while she told him about the alliance between the Eleven and the Ravenous. Investigating events at the Crucible of Souls, the Master realised that the Eleven had used the Crucible and the Matrix print of the Gallifreyan scientist Artron to give the entire universe the ability to regenerate, making them all potential food for the Ravenous. Working with and their, the "War" Master was able to give the Eighth Doctor the opportunity to "heal" the Ravenous while the Masters used the Crucible to restore the rest of the universe to mortality. Although the Time Lords requested Artron's Matrix print to give them the ability to grant new regeneration cycles to Time Lords, the Masters first used this to restore a past version of themselves to life with a new regeneration cycle. (AUDIO: Day of the Master)

The Master was a part of Project Blackstar which involved the destruction of Hydrosa in a weapons test. One native, Ilya saw him up close during the destruction. (AUDIO: The Edge of Redemption)

The Master visited the Siege of Saracassar to see the sights, and met Lyric. He offered to take her away from the planet, but refused to bring her sister too, forcing her to choose. (AUDIO: The Scaramancer) She went with him, and he kept her in his TARDIS observing her pain and guilt and forcing her to revisit the Siege numerous times, until she was hardened against them. Growing bored with her, the Master left her on an ice planet. (AUDIO: The Cognition Shift)

On the Time Lords' orders, the Master created the War Seeds, biological weapons designed to convert the population of entire planets into warrior species faithful to the Time Lords. (AUDIO: War Seed)

Posing as a Confederation emissary, the Master infiltrated Thabus to learn about brainwashing technology being developed there. After sometime his cover was exposed and he was tortured by Cato, the developer of the technology. His meddling on Thabus had enabled Cato's opponent, Gallia, to move against Cato successfully however and she allowed the Master to escape afterwards. (AUDIO: The Players)

The Master gave the order to destroy the world of Severine's people, leaving her and her mother the only survivors. He would later confess he hadn't understood the extent of their telepathic powers then, as he'd have tried to exploit them instead if he had. (AUDIO: The Last Line)

Cognition Shift scheme
After stealing the Infinity Chip from Skaro which he hid on Redemption, (AUDIO: The Cognition Shift) the Master desecrated the tomb of Cardinal Magos, one of his childhood heroes, and brought the body to Kurnos 5. He deliberately left a trail of artron energy for the Eighth Doctor to follow. On Kurnos 5, he spent decades searching for Magos' descendants planning to use his old laboratory to recall his mind from death and ask him where he could find the Cognition Shift. He succeeced and Magos told him it was in the Lehar system, just as the Doctor arrived. The Master trapped him in a force field, and used Magos' technologu to could take his body and his TARDIS. This enabled him to travel to the Lehar system without being detected by the CIA, who found the Doctor in the Master's body on Kurnos 5. (AUDIO: The Castle of Kurnos 5)

After having several "diabolical" adventures in the Doctor's body, (AUDIO: The Cognition Shift) the Master reached Nastrum, where, posing as the Doctor, pretended to build a sanctuary for refugees from the Time War. He also paid Dorada to bring him the Infinity Chip, while also being on the lookout for CIA agents. (AUDIO: The Scaramancer) When Dorada arrived, the Master, instead of paying her, used her to test the Shift and transported her mind into the body a local bird. His intention was to project his mind into every Dalek in the universe, but was stopped by the Doctor, who first took off the Infinity Chip from the machine and then used it to swap their bodies back. When Lyric, now become the Scaramancer, arrived to help the Doctor, he tried to pose again as the Doctor, but she saw through her deception and helped the Doctor paralyse the machine. The Master escaped from Nastrum by hypnotising Morski and have him brought back to Kurnos 5, to retrieve his TARDIS. (AUDIO: The Cognition Shift)

Plundering the Land of Fiction
The Master began scavenging the battlefield for abandoned Daleks, so he could extract from them useful devices to use as weapons. When the Daleks caught up with him and tracked down his TARDIS, the Master then escaped in the Land of Fiction through a time corridor. Knowing that the Daleks would pursue him, he twisted the tale of Perseus by preventing him to kill Medusa and convinced them both to help him overthrow the gods of Mount Olympus. Having sent Perseus to his death, he opened the time corridor to Medusa, granting her wish to leave this world, but also sending her straight against the Daleks pursuing him. In the following fight, the Daleks and Medusa killed each other, while the Master chose to remain in the Land of Fiction and plunder his weapons, so that he could use them to end the Time War. (AUDIO: The Wrath of Medusa)

As the Master wandered throughout the Land, taking possessions of various magical weapons from fabled creatures, his shadow acquired intelligence and a mind of his own. The Master didn't realise that until he was in the desert, dealing with the Devil for some magical golden bullets: the three of them would obey the Master, the other would be subjected to the Devil's will. The Master shot at his shadow, and he ran away from him, eventually falling in love with Poetry and becoming a real character. The Mastet tricked him into meeting with him in front of an audience, called him a threat to the world and tried again to shoot, but instead killed Poetry, destabilizing the entire Land. To remedy that, the Master helped the "Shadow Master" to summon a "shadow TARDIS" and use the energy of both that machine and his TARDIS to give new energy to the Land. He then seemingly agreed to leave Mount Olympus and the Land, but in reality he tricked again the Shadow Master, making him look into a magic mirror who sent him back to the limbo where fictional characters reside before they birth. (AUDIO: The Shadow Master)

The Master sought the fragments of the Encyclopaedia Omnia, which were held by different variations of Professor Moriarty, killing variations of Sherlock Holmes and John Watson as he did so. For the last fragment he challenged Moriarty to a contest with each to kill the last variations of Watson and have the other deduce how they'd done it. The Master killed and replaced one Watson's Sherlock and worked with this Watson to investigate the death of two doppelgängers of his, in truth variations the Master and Moriarty had already killed for Moriarty to solve. The contest resulted in a tie, as both the Master and Moriarty deduced the other's method, so the Master broke the tie by killing Joanna Watson and Moriarty himself. With his collection of the Encyclopaedia complete, he left the last surviving Watson with instructions to document the events he'd endured. (AUDIO: The Adventure of the Deceased Doctor)

Seeking immortality, the Master infiltrated the story of Dorian Gray and influenced Sibyl Vane so she would aid him. He eventually captured Dorian and planned to transfer his life force into himself, however Sibyl overcame his influence and reversed the process, supercharging Dorian's immortality to the wounded Master's amusement. After Dorian and Sibyl ordered him to leave, the weakened Master decided he'd lingered too long in fiction and resolved to return to face reality. (AUDIO: The Master of Dorian Gray)

Creator of the Daleks
After he found out that Crazlus was in a position of power in the CIA, the Master constructed a plan to interfere in the creation of the Daleks with the Anti-Genesis code. After poisoning himself with the blood of a Dolthradian Dragon, the dying Master returned to Gallifrey and requested a Time Lord funeral, though Narvin denied him and ordered Crazlus to have the Master's body burnt with the Infernal Toxicant, but Crazlus instead used the Toxicant to cure the Master from the poison. The Master then took control of Crazlus' body and went to Narvin, pretending that "Crazlus" had found the Anti-Genesis code in the Master's TARDIS computer, and tricked Narvin into leading him in to the Matrix to find the real code. Once he was in possession of the code, the Master travelled to Skaro during the Thousand Year War, and arranged for Davros to be killed during the bombardment where he was originally crippled. (AUDIO: From the Flames)

Infiltrating the Kaled scientific elite by pretending to be Davros' uncle "Sovrad", the Master became the new head of scientific development, and tricked Davros's former assistant, Elrond, into giving him Davros's last discoveries, allowing the Master to modify the Mark III travel machine into a proper Dalek casing with a biogenetic accelerator, which he used on Elrond to speed his biological evolution into a Dalek mutant, creating his first Dalek, which he sent against the rest of the Kaled elite, transforming them all into Daleks. In the midst of his work, the Master was reached by Lamarius, a Time Lord agent sent to kill him, but he captured and interrogate her, learning that she was also a renegade for using a time torpedo to avoid the destruction of a planet where her family lived, and, after infecting her with the same mutant radiation the Kaleds were affected from, sent Lamarius back to Gallifrey to mock Narvin and President Livia about her failure. (AUDIO: The Master's Dalek Plan)

After sealing the bunker by blowing up the entrance and promoting Elrond to Dalek Supreme, the Master gave him the order to build five thousands Mark III travel machine as he used his TARDIS to move forwards in time to the moment the Time Lords sent the Fourth Doctor to interfere in the creation of Daleks. The Master set up an ambush for the Doctor and his companions and had his Daleks kill them. He then ordered the Daleks to deliver a genetic bomb to the Thals, so that they could use them against the remaining Kaleds and turn them into mutants, to be put inside the newly-built Dalek cases and form an army. (AUDIO: Shockwave)

The Master then led the Daleks into a military campaign which eventuated in his total victory over the universe. However, immediately after this victory, the Master began to have visions of another man warning him against the treason of his Daleks by showing him a vision of his extermination for behaving too much like an "inferior" being. He then revealed himself as the Unbound Master from a parallel universe, brought to N-Space by the Dalek Time Strategist in an attempt to avert the "War" Master's changes. The "Exiled" Master convinced the "War" Master that the Daleks would rebel against him as they did with Davros, and the "War" Master agreed to help him and the Dalek Time Strategist avert his victory. He led them to Mussafa, when he originally connected Crazlus to his TARDIS, and contacted his past self to trick him into bringing Crazlus to them so that he could be killed. As a result of Crazlus's death, the Master's plan was made impossible, and the timeline resulting from his success was erased: the present Master dissolved, the Daleks from the original timeline came back into existence, and the connection between the "Exiled" Master and N-Space became tenuous.

The Daleks attempted to capture the Masters, but they escaped into the "War" Master's TARDIS. The Daleks went into pursuit and attacked, with their first blow causing the "Exiled" Master to fall into a wormhole in the fabric of reality. Their next strike heavily damaged the TARDIS, sending it on a crash course, while the Master was retrieved by the Daleks, who blackmailed him into serving them in exchange for the location of his lost TARDIS. (AUDIO: He Who Wins)

The Daleks sent the Master to Gardezza, where he posed as the Doctor, using his reputation to gain the trust of the Gardezzans. The Master located his TARDIS on the planet and betrayed both the Daleks and the Gardezzans to retrieve it. Inside, he received a call to return to Gallifrey and left to answer it. (AUDIO: Beneath the Viscoid)

A mission from Gallifrey
After he was captured upon arriving on Gallifrey, Celestial Intervention Agency Coordinator Romana sent the Master alongside Leela to interrogate Finnian Valentine for information on a power source for a temporal weapon he'd deployed, promising that he would be pardoned for his crimes in return. On the planet, he and Leela found Finnian had been duplicated when the temporal weapon had torn his timeline in two and used his laser screwdriver to stun both of the Finnians. He and Leela interrogated them, to no avail, so eventually he simply threatened to kill the two Finnians until he learnt that Arcking had the power source, and then killed them both anyway. On the way back to Gallifrey, the Master expelled Leela into the Time Vortex and headed to Arcking to seize the power source for himself. (AUDIO: The Devil You Know)

Rescuing Cole Jarnish
Travelling to hospital planet Arcking multiple times, the Master, under the alias "Dr Keller", attempted to possess an ancient power, known as the Heart, that had resisted the ravages of the Time War, and even prevented unnatural death. On Arcking, the Master met Cole Jarnish, a pilot who suffered from survivor's guilt as he was the sole survivor of an incident that had killed the rest of his crew. Intrigued by his desire to help the innocent people affected by the Time War, the Master hinted to Cole that he would be able to help him realise this idea. When Arcking was eventually overrun by a Dalek invasion force, the Master saved Cole's life by bringing him along in his TARDIS as he made his escape. (AUDIO: The Good Master)

After travelling with him for a while, the Master was accused of being too disengaged towards the Time War by Cole, and was challenged to play a more active role in assisting the people suffering under the destructive effects of the war. While the Master deflected this accusation by referring to his status as a Time Lord, and how it forbade him from interfering directly, he in turn offered Cole a challenge; he would allow Cole pick out a planet in peril and take him there, so he could try and save its people from destruction with whatever means he saw fit. Cole's choice fell on a primitive farming planet. Upon landing on the planet, the Master reminded Cole that he was not allowed to meddle directly, and so decided to take some time off to build his own vineyard and try his hand at cultivating grapes while he left Cole to his own devices. (AUDIO: The Sky Man) During this time, he stopped an alien parasite from consuming the planet. (AUDIO: Boundaries)

On trial before the Vectors
The High Vectors captured the Master whilst he was running his vineyard in order to put him to trial, so they could sentence him to death for his actions in the War. (AUDIO: The Players, Boundaries) They first threw him in the Forest of Penitence together with other guilty people, but the Master understood where he was and tricked all the other people into confessing they were guilty and being turned into trees. He was then taken out of the Forest and put explicitly on trial in front of the Vectors. (AUDIO: The Forest of Penitence)

During the trial, in order to prove he was not as evil as they thought, the Master recounted to the Vectors what happened on Trabus (AUDIO: The Players) and how he saved Cole's planet from the alien parasite. (AUDIO: Boundaries) During all the trial, the Master was kept prisoner by Severine, a young telepath preventing him from planning an escape. (AUDIO: The Last Line)

Eventually, the Master called on the Doctor to defend him, (AUDIO: Boundaries) and the Vectors then summoned the Tenth Doctor to their tribunal. The Doctor didn't defend the Master, but he pleaded for the Vectors to spare him nonetheless, to avoid the moral corruption brought upon them by the War. His pleads were rejected, and the Doctor tried to make the Master evade, but his attempts were twarted and the Master eventually was brought to be sentenced. However, at the time the Master revealed he had been playing both Severine and the Doctor all along, so that he could be connected to the entire Vector system and used it to destroy them. The Master took the Doctor out of the destruction and brought him back to his TARDIS, before he went on with his plan with Cole. (AUDIO: The Last Line)

Targeting the Stagnant Protocol
Whilst running his vineyard, the Master targeted the Stagnant Protocol, creating a gateway into the time lock surrounding their civilisation. Purporting to be a Time Lord ambassador, he attempted to make inroads into the Empress' court but all his attempts to win round nobles with promises of power proved fruitless. Over the course of his campaign, the Master encountered a rival, Calantha who was pursuing her own ambitions and began having regular lunches with her. The Master finally managed to convince Prince Gardam that he could put him on the throne as a champion of the people, but was outmanoeuvred by Calantha who released a tamer variant of a plague, creating a crisis which hastened her own rise to power. With Gardam banished to an outer planet on plague duties and Calantha ascending to Empress, the Master conceded he'd lost the battle but vowed to win the war. (AUDIO: The Sincerest Form of Flattery)

The Master obtained a vial of the true plague from UNIT by manipulating Jo Jones, contaminating all her memories of her uncle by stealing his identity even after she saw through the ruse. (AUDIO: A Quiet Night In) He experimented on the plague at a research station run by Nyssa, who he left trapped in quarantine after she deduced his true identity. (AUDIO: The Orphan)

Returning to the home world of the Stagnant Protocol, the Master unleashed the true plague and rose to the position of Regent Chancellor by aiding Calantha as the situation grew increasingly desperate. He provided a cure, though refused to reveal its composition to anyone, and grew his influence over the nobility by learning secrets the plague forced its sufferers to expose. Calantha eventually moved against him and imprisoned him, torturing him by subjecting him to her tamer form of the virus, which he hadn't vaccinated himself against, and depriving him of food in order to force him to reveal the cure. The Master eventually faked his death and re-emerged at the public funeral for him Calantha had arranged, exposing the truth about her recent dealings with the Daleks and closing his gateway as a Dalek fleet attempted to arrive through it. With the public turning on Calantha, the Master revealed her role in the plague and convinced her to flee in a shuttle. In the aftermath, the Master assumed control of the Stagnant Protocol but said he would leave them to their own devices for the most part, as he was confident in their obedience. (AUDIO: Unfinished Business)

Activating the Heavenly Paradigm
After Cole's attempt to save the peaceful population of the planet backfired when he inadvertently turned them into a race of warlike semi-robotic creatures, the Master helped him escape the planet and assured him that he would help him to undo his mistake. (AUDIO: The Sky Man)

The Master and Cole travelled to Stamford Bridge in the 1970s, where they located a Time Lord repository, and the Master revealed the reason he saved Cole's life and supported his attempt to save the people of the farming planet was to turn him into a paradox powering a paradox, with the resulting temporal energy collected in Cole to be used to power the Heavenly Paradigm. Despite Cole's pleas, the Master sacrificed him to the machine, wanting to use it to create a new and better timeline, and thus end the War. The plan backfired, however, when the Master's direction to make a "better" timeline, simply proved both far too big and far too vague for the Paradigm to handle, and the changes soon spun out of control.

The Master watched in horror as his meddling unintentionally resulted in both the Time Lords and Daleks to win several battles they had once lost, and vice versa, completely altering the state of the Time War to one that was ultimately more favourable to the Daleks. Because of this, (AUDIO: The Heavenly Paradigm) he then saw the Dalek Emperor take control of the Time Lords' Cruciform, (TV: Utopia; AUDIO: The Heavenly Paradigm) leading him to foresee that he would be killed by the Emperor if he stayed. Choosing to flee the Time War (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe) and declaring it "lost", the Master was frightened into running from the War.

For a time, the Master corrected and observed changes made to the Time War by the Paradigm. Still scared and tired of the fighting, he fled to the far end of time and sent his TARDIS away to Gallifrey without him and used a Chameleon Arch to turn himself into a human baby, intending to eventually resume control of his body once the Time War had ended. (AUDIO: The Heavenly Paradigm) The baby would come to be known as Yana, growing into a benevolent absent-minded scientist who attempted to help humanity stave off its impending doom on Malcassairo via the Utopia Project. (TV: Utopia)

As the War drew to a close, the War Doctor was ordered to search for the Master only to report back to that he could not locate him. Understanding that the Master had abandoned "all of us" to "run for cover", the Doctor expressed his doubt that the Master would seen again, at least not until the war was over. (PROSE: Engines of War) After the end of the Time War, the Ninth Doctor did not expect to ever see the Master again, (AUDIO: Flatpack) believing all the Time Lords bar himself to be dead. (TV: Dalek)

Returning from the Chameleon Arch
As the Project neared completion, Yana met the Tenth Doctor, Jack Harkness and Martha Jones when they were rescued from the Futurekind. Overhearing conversation between the Doctor and Jack about things such as time travel, Daleks, and regeneration, Yana became visibly upset. Martha, recognising the fob watch Yana had in his possession as a chameleon arc, inadvertently drew his attention to it, breaking the perception filter placed on it. Hearing the voice of one of his Time Lord self's past incarnations up to the War Master himself, commanding and entreating him to remember who he really was, a mesmerised Yana opened the watch and turned back into the Master. (TV: Utopia)

Death
The Master then locked the Doctor out of Yana's lab, and opened the gate keeping the Futurekind at bay to keep the Doctor occupied as he ravaged Yana's lab. After Chantho threatened him with a gun to stop him destroying their work, the Master electrocuted her with a loose set of power cables, angered that she was never curious of the fob watch during their decades of working together, and left her for dead. However, Chantho used the last of her strength to pull a laser gun on the Master while his back was turned, and shot him in the chest before she died.

Fatally wounded, the Master slithered into the Doctor's TARDIS while the Doctor watched on and deadlock sealed the door shut to keep the Doctor out. Finding the idea of dying by the hand of "an insect and a girl" undignified, the Master decided to regenerate into was as young and strong as the Doctor was. (TV: Utopia) would acknowledge on her Spacebook profile that the Master had died for the seventeenth time after having "stopped being a human", and that it was only after his eighteenth death that the Master became Missy. (PROSE: Girl Power!)

Killed by the Barber-Surgeon
During the Time War the Master was tasked with assassinating the Barber-Surgeon by the War Council, accompanied by two handlers. (AUDIO: The Abyss) The Barber-Surgeon killed the Master, which he later described to the War Doctor. (AUDIO: The Horror) The War Doctor found the Master's body, which had been arranged as a clue to point him towards the portal to the Barber-Surgeon's dimension, and even shed a tear for his old foe, wondering why he hadn't just run. (AUDIO: The Abyss) After the Barber-Surgeon was erased from history, all the deaths caused by his campaign were undone. (AUDIO: The Horror)

Alliance with the Doctor
At some point during the Last Great Time War, the Master regenerated into a new incarnation. Now in the body of a small child, the Master fought further along in the Last Great Time War than his predecessor. Despite this, he was able to manipulate events to write out many of his actions during the War, even though it was timelocked. (COMIC: The Judas Goatee) The Master made a deal with the War Doctor to end their old ways of fighting to become allies, fighting alongside the Doctor and his companion, the Squire during the period of the War in which the Cyclors allied themselves with the Daleks. (COMIC: The Organ Grinder)

The Doctor and the Master travelled to Veestrax, where they saw a broken wall with "Exterminhate" written on it. The Master told the Doctor that he hadn't written it. The Doctor then asked for the Master's help with destroying the planet. (COMIC: Outrun)

He arrived on Golgauth with the Doctor, asking what he intended to do, to which the Doctor said "what [he] [had] to". (COMIC: The Then and the Now, The Organ Grinder) The duo soon encountered the Volatix Cabal, together killing one of its members. They then encountered Alice Obiefune, who had travelled in the Master's TARDIS from after the War had ended. The Master set about tethering his future TARDIS to the Doctor's while the Squire set about saving Alice from the Volatix Tendrils.

With both TARDISes in tow, they travelled beneath the surface of Golgauth, where an Overcaste rebel base was located. The Master and the Doctor revealed a Volatix spy in the group and neutralised him. The spy revealed that he had called for help and moments later a Cyclor tore off the roof of the base. (COMIC: The Organ Grinder) The Master used a device to summon a squadron of Gallifreyan ships to attack the Cyclors. He used this chaos of the Cyclor attack to flee, sneaking into his future self's TARDIS to escape the Time War.

However, he discovers that it was his future self that implanted the chronal tumour on his console in the first place. At some point in his now aborted future, he was to operate on the brain of his TARDIS, which would result in the chronal tumour that protruded from one side of the console. (COMIC: The One) But since escaping the Time War in his TARDIS would preclude him from implanting the tumour in the first place, the resulting paradox shattered reality in "a cascade of temporal possibility." Subsequently, the chronal tumour began to react to the Psilent songbox. While the Master attempted to disarm the device, it was too late, and the resulting temporal bomb left the time-ship spiralling out of control. With the Master's timeline collapsing as a result of the paradox, Alice's intervention in the War and the life he now never led was erased, leaving the Master, reverted to his previous incarnation, fleeing the event horizon of the temporal bomb. (COMIC: Fast Asleep)

Personality
This incarnation of the Master, while cruel, would put on a front of being kind and charming, but would drop the façade the instant it was time to act. (AUDIO: Beneath the Viscoid) When the telepathic entity, the Heart of Arcking, questioned him on whether he was truly as evil as he considered himself after reading his mind, the Master was briefly caught off-guard by the question, and hesitated momentarily in answering before he gathered himself and dismissed the notion, vehemently denying that he had any benevolent sides to his personality. (AUDIO: The Good Master) When given the chance to seek a form of redemption, the Master rejected it on the grounds he did not feel guilty for any of his actions, (AUDIO: The Forest of Penitence) and would later argue his actions resulted in good whilst on trial before the Vectors. (AUDIO: The Players, Boundaries)

He wished to save the universe from the Last Great Time War so that he could rule over it afterwards, (AUDIO: The Heavenly Paradigm) and "enjoy [his] victory", (AUDIO: The Devil You Know) claiming that the only faction he fought for was his own person. (AUDIO: Beneath the Viscoid) He rejected the prospect of an alliance with Zeus to takeover reality, not wanting to be subservient to a greater power. (AUDIO: The Wrath of Medusa)

While he would openly admit to allowing the destruction of individuals and places he found "dull", the Master was adamant to ensure the things he found "beautiful" would be left unharmed, such as roses (AUDIO: Sins of the Father) or his vineyard. (AUDIO: Boundaries) After overthrowing the Greek Gods in the Land of Fiction, he kept Mount Olympus intact for his own use. (AUDIO: The Shadow Master) He also claimed that would only destroy the universe in the hopes of building something better in its place, in contrast to his immediate successor. In the aborted timeline in which his successor unleashed the entropy wave on the universe it was the "War" Master who decided to save the universe, by creating a paradox by poisoning himself and all his other selves and letting Missy be devoured by the wave. (AUDIO: Masterful)

While he declared it "inappropriate" to have been killed by a female "insect", (TV: Utopia) the War Master equally held everyone in similar disregard unless it benefited him, even planets, stating he only had allegiance to himself. (AUDIO: The Good Master) He was unable to empathise with others, yawning at a mother's drive to save her race being born from her dead husband and her son. On a large scale, he also had little to no regard for the other sentient species of the universe, dismissing the majority of them as lesser beings and primitives, and declaring in private that he did not care "one iota" for their plights under the Time War. (AUDIO: Beneath the Viscoid) His disregard for others was so great that he even secretly impregnated several women with living weapons, without a care for the consequences of his actions, (AUDIO: Concealed Weapon) and thought nothing of causing the downfall of the Vectors, a civilisation older than the Time Lords, to save himself. (AUDIO: The Last Line)

The Master found enjoyment in the death of others, even killing for his own amusement, believing the most pointless of murders to be the most "fun", (AUDIO: Master of Worlds) and enjoyed tormenting his intended victims before their demise, citing an enjoyment for a "ticking clock". He would even give them a chance at survival for further torment. (AUDIO: Concealed Weapon) The Master was known to taunt Daleks, (AUDIO: The Good Master, The Wrath of Medusa) and he also found amusement in the misery of the Time Lords, particularly when it came to Narvin. (AUDIO: Sins of the Father) He particularly tormented John Watson, using hypnosis to trick him into eating the cooked remains of Sherlock Holmes, (AUDIO: The Adventure of the Deceased Doctor) and laughed at Martine King becoming adrift in space due to hallucinations caused by swenyo. (AUDIO: The Persistence of Dreams) This Master seemed to take a particular pleasure in tormenting the Doctor's companions, including monologuing at length to Liv Chenka about the damage caused by bullets before shooting her, (AUDIO: Day of the Master) manipulating Jo Jones to the point she could not trust her own memories, (AUDIO: A Quiet Night In) trapping Nyssa in a quarantine, (AUDIO: The Orphan) and laughing as he threw Leela into the heart of the Time Vortex. (AUDIO: The Devil You Know) He also taunted River Song that he'd overcome his previous selves' inability to hypnotise her, which he used to force her to forget their encounter. (AUDIO: Concealed Weapon)

The Master did treat his rivals cordially. He had regular dinners with Calantha as they both schemed in the Stagnant Protocol's court, (AUDIO: The Sincerest Form of Flattery) and made a gentlemen's agreement with Professor Moriarty for a contest. (AUDIO: The Adventure of the Deceased Doctor)

When comparing him to the "decayed" incarnation she was used to, Leela claimed that the "War" Master was "focus[ed]", "making guesses", and "plotting". In comparison to his past self, the Master claimed he was now "civilised, pleasant, [and] reasonable", which was denied by Leela. (AUDIO: The Devil You Know) The "War" Master believed that none of his other selves could have faced the Time War as he had, challenging them to look at him in the eye. (AUDIO: Masterful)

After his use of the Heavenly Paradigm caused the Dalek Emperor to take control of the Cruciform, the Master, driven by the fear of his failure, fled the end of the universe and used a Chameleon Arch to turn himself into a human baby to hide from the Time Lords and wait out the war in a safe place. (AUDIO: The Heavenly Paradigm)

Under the Chameleon Arch, Professor Yana was a benign old man who had lost faith in the Utopia Project. His spirit was revitalised by the Tenth Doctor, and the two shared a mutual admiration. Yana was considered a genius by the Tenth Doctor. He was also somewhat scatterbrained and slightly lacking in self-confidence, at one point referring to himself as "a stupid old man." Also, like the Tenth Doctor with Martha Jones, Yana was oblivious to Chantho's feelings for him.

After returning to his true identity, the Master became cold, ruthless, and dignified, but also abusive and condescending, citing that he had the right to attack Chanto when she pointed a gun at him. He was extremely aggressive towards Chantho after regaining his memories, stating that her constant cultural ticks drove him "insane" during their time together. He also ferociously resented her for not thinking that she could set him free from the fob watch. The Master held his 'human' self in contempt, seeing it as merely a disguise so perfect that he forgot his own identity. (TV: Utopia)

When given the chance to rest from the Time War, the Master spent his time cultivating wine. (AUDIO: The Sky Man) He was surprised at how protective he felt towards his vines and took great pride in their growth. He was even "not afraid to admit" that he was "but an amateur" at the art. Finding himself "perfectly content" in life while in that vineyard, he considered settling down in France with a small vineyard if he ever wanted to retire. While watching a meteor storm one night, he remarked that he enjoyed watching the falling "benign cosmic debris" and "could almost forget" the War on such nights. (AUDIO: Boundaries)

Though he thought "inappropriate" to have been killed by a female "insect", the Master welcomed his regeneration in a grandiose fashion, declaring that "the Master [was] reborn." (TV: Utopia)

Skills
Enjoying "slow-working plans" that gave him ample opportunity to study the small effects that resulted from his ploys, (AUDIO: The Sky Man) the Master would plan ahead with every scheme, preparing for every eventuality, even his capture. (AUDIO: Sins of the Father) He would also research his targets, and manipulate their history to his benefits. (AUDIO: Concealed Weapon) He also showed a great capacity for patience in the implementation of his schemes, being willing to wait for prolonged periods of time to find the perfect subject to manipulate, or for the right time to strike. (AUDIO: The Good Master, The Sky Man) He was frustrated when his plans did not work, but was willing to lose a battle in hopes of winning the war. (AUDIO: The Sincerest Form of Flattery)

The Master was adept at manipulating individuals quickly in the heat of the moment, (AUDIO: Beneath the Viscoid) using his choice of words and tone of voice to break down their character with his assessment on their quirks and decisions. (AUDIO: Call for the Dead) He deliberately used a particular interpretation of Greek mytology to turn Perseus against the Gods. (AUDIO: The Wrath of Medusa) The Master was also adept at integrating himself into other's confidences. He won the trust of the people of Callous after helping turn their mine's favours around and playing a clown for children, (AUDIO: The Glittering Prize) and took on multiple roles in the story of Dorian Gray to manipulate his life. (AUDIO: The Master of Dorian Gray)

This Master was particularly adept at manipulating the Doctor. He let Alice Pritchard summon him knowing the Eighth Doctor would be unable to resist helping her even as she subconciously drained him, (AUDIO: The Missing Link) left a trail designed to lure the Doctor to Kurnos 5 so he could execute his plan, (AUDIO: The Castle of Kurnos 5) and anticipated the Tenth Doctor's actions as part of his scheme to escape and destroy the Vectors. (AUDIO: The Last Line)

Appearance
In his seventeenth incarnation, (PROSE: Girl Power!) the Master originally looked old, having white hair and blue eyes. Though he started his life clean-shaven, (COMIC: Fast Asleep) he eventually grew a scruffy white goatee beard. (AUDIO: Beneath the Viscoid)

After use of the Chameleon Arch, he regressed into a baby. (AUDIO: The Heavenly Paradigm) When Professor Yana met the Tenth Doctor, he resembled a slightly younger version of his original self, having aged naturally as a human. (TV: Utopia)

He wore an ivory shirt with a narrow collar, sometimes with sleeves rolled up, (AUDIO: Beneath the Viscoid) a black cravat tie, and black trousers. He also wore a single-breasted waistcoat done in emerald-and-brown stripes cotton, (AUDIO: The Master of Callous) gunmetal grey tweed (AUDIO: Rage of the Time Lords) dark beige herringbone, (AUDIO: Day of the Master) or mustard yellow moleskin. (AUDIO: The Sincerest Form of Flattery) He also wore a jacket of tweed done in charcoal, (AUDIO: The Heavenly Paradigm) or olive green. (AUDIO: The Sincerest Form of Flattery) He would occasionally replace the cravat with a burgundy bow tie and also wear tan leather gloves. (AUDIO: The Sincerest Form of Flattery) During his encounter with UNIT, he wore a burgundy moleskin overcoat. (AUDIO: Master of Worlds) When he was Yana, he wore the same shirt alongside a black cravat and a wine brocade waistcoat which housed a Chameleon Arch biodata module, disguised as an ordinary fob watch. (TV: Utopia)

During his walks on Arcking, he wore a Grav-Suit over his clothes. (AUDIO: The Good Master)

In a timeline in which he altered the creation of the Daleks, the Master stole the black uniform of a Kaled Military Elite with embroidered white eye logos on the collars. (AUDIO: From the Flames)

Other references
As recorded in the Masterplan Journal left behind by, had carved the image of "Wizard of Oz" 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 by the Spy Master, the Thirteenth Doctor remembered, amongst many others, the War Master in order to break out of the computer system. (TV: The Timeless Children, TV: Utopia)

Behind the scenes

 * Derek Jacobi previously played the role of the Master who served as a companion to Richard E Grant's Ninth Doctor in Scream of the Shalka. Jacobi also voiced Martin Bannister and Doctor Who in the Doctor Who Unbound audio drama Deadline.
 * This incarnation stars in, and derives his official name from, The War Master audio series by Big Finish Productions, the first spin-off focusing an incarnation of the Master. Naturally, "the War Master" was the internal name used to distinguish the incarnation of the Master portrayed by Derek Jacobi in Masterful, as revealed in the behind-the-scenes track for its release.
 * Battles in Time released a card for this incarnation, distinguished from by the title "The Master (Pre-regeneration)".