A return for this long-dormant feature, this time focusing on the race known as the Time Lords, from the popular British SF series Doctor Who.
It should be noted that for this article I drew on the TV show alone. The spin-off novels and comics feature a ton of further information on Gallifrey, Rassilon, the Time War and so on, but these are of questionable canonicity and sometimes completely contradict one another. As a result, the only source I used was the TV show.
Gallifrey, the homeworld of the Time Lords.
The Time Lords are a humanoid species originating on the planet Gallifrey. The Time Lords are noted for their mastery of time and space, as they were apparently the first species in the universe to develop time travel technology. Originally they pursued an aggressive, interventionist policy but several disasters led to them instead adapting a policy of non-intervention in the affairs of other worlds and times. Several renegade Time Lords have broken this rule, some very frequently, to the consternation of the rest of the race.
The Doctor is a Time Lord and the most well-known being of that species. The Time Lords appeared irregularly throughout Doctor Who's original run. When the second run of the show began in 2005 a new backstory was adapted stating that the Time Lords had been annihilated in a mutual war of destruction against the Daleks, with the Doctor as the sole survivor of the race. The relaunch also suggested that the Time Lords had become militaristic and belligerent during the war, and ultimately became as dangerous to the rest of the universe as the Daleks.
The Capitol on Gallifrey and one of the Time Lords.
The planet Gallifrey was located in a galaxy approximately 250 million light-years from Earth. Gallifrey was part of the Kasterborous cluster of seven stars, all with notable habitable worlds. Gallifrey was known as the Shining Jewel of the Seven Systems. There were six planets in the Gallifreyan system (including Gallifrey itself). One of the neighbouring planets, Karn, was also (barely) habitable.
By the time of the Time War, Gallifrey had become a somewhat desolate planet, dominated by deserts, volcanoes and towering mountain ranges. The planet was several times larger than Earth but apparently enjoyed an Earth-like gravity field, suggesting it was not as dense in terms of its geophysical make-up. In the absence of evidence to the contrary, it is assumed that the Gallifreyan humanoids evolved on the planet over a period of hundreds of millions of years, like the humans of Earth. It may be that Gallifrey's desolation by the time of the Time War may have been a result of industrial pollution or worldwide wars in the past, as well as the Time War itself (though it should be noted that pre-Time War Gallifrey is also shown to be fairly desolate, though much less volcanically active). Given the Time Lords' supreme technological mastery, including the ability to move planets and travel through time, it is unclear why they never used their skills to make Gallifrey a more pleasant place to live.
The length of the lifespan of Gallifreyan civilisation is not entirely clear. It has been suggested that the Gallifreyans achieved sentience and technological mastery some seven billion years ago, with one Time Lord claiming that they have had transmat technology since the universe was 'less than half of its current size'. However, this may have also been a reference to the Time Lords using such technology in the distant past, having travelled back to a time before their own world was formed. Another reference to the Time Lords leading a coalition of races in a war against the Racnoss Empire before the Solar system formed (roughly five billion years ago) could also be referring to a war fought at a certain point in time chosen by the Time Lords, rather than the suggestion of billions of years of continuous existence by a single species.
Omega, as encountered during his long exile in the antimatter universe.
What is known is that Gallifreyan civilisation underwent its most profound transformation when two scientists, Rassilon and Omega, created time travel technology. Much of the technical work was done by Omega, who piloted a craft to trigger a nova in another star and then capture the star at the moment of its collapse into a black hole, creating an inexhaustible supply of energy. The experiment was a success, but Omega's craft was apparently destroyed in the process. It was later revealed that Omega in fact survived, but had been cast through the black hole into an antimatter universe, where he would remain trapped for many, many years (from his perspective, centuries and potentially several millennia). Rassilon, completing his work, created a transtemporal link to the black hole underneath the Capitol, the largest city on Gallifrey. This link became known as the Eye of Harmony and would provide Gallifreyan civilisation with its power. The Hand of Omega, the 'stellar manipulator' used by Omega to trigger the nova, survived the incident and was placed under high security on Gallifrey.
Over the following decades, Rassilon founded what became Time Lord civilisation. The earliest space/time vessels known as TARDISes (Time And Relative Dimension In Space) were built. A time lock was established on both Gallifrey's past and future, preventing Time Lords from travelling back or forth. This lock also seems to have prevented Time Lords from crossing one another's time streams (in all but the direst of emergencies), ensuring that Time Lords encounter one another and Gallifrey always on contemporary terms.
Rassilon in his final incarnation, as encountered during the Time War.
Rassilon also developed the Imprimatur, a genetic modification which allowed Time Lords to endure the rigours of time travel and was used to form a symbiotic bond between each Time Lord and his or her TARDIS. It has been theorised that the Rassilon Imprimature was the piece of genetic engineering which granted the Time Lords both a tremendously extended lifespan (at least seven centuries per incarnation) and the ability to 'regenerate' into a new form twelve times. This would give Time Lords lifespans measured in the millennia. However, Time Lords taking part in time travel would also be exposed to dangerous and frequent hazardous situations and many would likely burn through their regenerations much more quickly.
It is unclear if all Gallifreyans were given this ability, and thus the terms 'Gallifreyan' and 'Time Lord' are interchangeable, or if only a small elite of Gallifreyans were transformed thusly into Time Lords, with the bulk of the race consisting of the shorter-lived 'original' humanoids. It is known that the process granting regenerations is transferable to humanoid races from both Tremas and Earth, suggesting that non-Gallifreyan Time Lords are possible. Whether any exist beyond the one confirmed (the Master, though originally a Gallifreyan, transferred his consciousness into a human body on Earth which was subsequently granted the power of regeneration during the Time War) is also not known. However, it is clear that Time Lords nearing the end of their life cannot simply get a new set of regenerations, suggesting that the process can only be used once per humanoid body.
During Rassilon's lengthy period of rule, the High Council of the Time Lords was established, with himself as its President Eternal. During Rassilon's rule the Time Lords found themselves at war with a species known informally as the 'Great Vampires'. A brutal and bloody war was fought through time and space which the Time Lords won by the deployment of extremely formidable vessels known as bowships. It is possible that Gallifrey itself was threatened during this war, which may have led to Rassilon's creation of the Transduction Barrier, an impregnable forcefield surrounding the entire planet. Though the Time Lords won the war, they failed to kill the vampire leader, a task finally accomplished many millennia later by the Doctor (who found the vampire leader hiding on a planet in another dimension, E-space).
Following this period, the Time Lords appear to have spent at least some time as an aggressive, expansionist and interventionist species. The Time Lords brought various species to Gallifrey and made them fight to the death in an area called the Death Zone. They were worshipped as gods on the planet Minyos and the Time Lords gave the Minyans advanced technology (including a very primitive and painful form of regeneration). However, the Minyans used their advanced technology to destroy themselves and their planet, with only a small group escaping into space to colonise another planet. Rassilon also created a powerful weapon which removed the target from space/time altogether, the Demat Gun, though its use was heavily restricted.
After this time the Time Lords seem to have become wiser and less cruel. The Death Zone was shut down and a policy of non-intervention in the affairs of other worlds and times was adopted. Rassilon succeeded in developing a form of immortality, but also became aware of how dangerous it was. He apparently died, taking the secret with him. His body was entombed in the Tomb of Rassilon within the Death Zone, to discourage grave-robbers. Curiously, despite lying in state for thousands of years, Rassilon's body never decayed.
In the meantime, Time Lord civilisation continued along fairly without incident until the arising of two young men from the Time Lord Academy. One would become known as the Doctor and another, originally his best friend, would become known as the Master.
The Doctor and Susan stealing the TARDIS from the repair dock on Gallifrey.
The Doctor's original name and status on Gallifrey was not known. What was known was that he took that name for himself and stole a Type 40 TARDIS whilst it was in the repair dock. He fled Gallifrey with his granddaughter (who eventually took the human name Susan) and disappeared into the space/time vortex. The reasons for the Doctor's flight are also unclear: it's been suggested he was simply bored and wanted to see the universe, whilst others suggest he might have been involved with the Celestial Intervention Agency (CIA), a body which officially did not exist but which carried out clandestine and deniable operations involving other species. The Doctor apparently took with him the Hand of Omega, the stellar manipulator used to create the Eye of Harmony, suggesting he had a grander scheme in mind.
The Doctor fled to Earth in the year 1963 (where the TARDIS adopted the form of a local police telephone call box), where he had the Hand of Omega buried in a churchyard and Susan enrolled at a local school. His further plans were not known, as the intervention of two of Susan's teachers, Ian Chesterton and Barbara Wright, caused him to dematerialise the TARDIS. At this point the reason the TARDIS was in the repair dock became clear: its chameleon circuit jammed, leaving it in the shape of a police box near-permanently, and it became impossible to steer. Instead, the TARDIS would randomly leap from world to world and catastrophe to catastrophe, embroiling the Doctor and an ever-changing roster of companions into many different adventures.
The Time Lords were aghast at the Doctor's interventions but were unable to intercept him, as he stayed on the move and the random movements of his TARDIS were completely unpredictable. It's possible this state of affairs would have continued, except that the Doctor - now in his second incarnation - finally encountered a situation that was way too large for him. An alien race allied with a renegade Time Lord known as the War Chief had used stolen Gallifreyan technology (primitive proto-TARDISes known as SIDRATs) to imprison hundreds of thousands of soldiers from throughout Earth's history on a distant planet and forced them to fight one another. Though the Doctor was able to defeat the War Chief and his alien superior, the War Lord, he was unable to rescue all of the different soldiers and had to call in the Time Lords to fix the situation. The Time Lords agreed, but forced the Second Doctor to stand trial for his crimes.
The Doctor argued passionately that the Time Lord policy of non-intervention had allowed the arising of powerful hostile alien races, some of them also pursuing time travel technology (such as the Daleks). The Time Lords believed that the Doctor had a point. They punished the Doctor by forcing him to regenerate ahead of time and exiled him to Earth in the late 20th Century, his TARDIS rendered non-operational. During this time the Doctor helped defend Earth from attacks by several alien species. The Doctor also encountered his best friend turned nemesis, the Master, at this time.
The Master in the thirteenth incarnation of his original body.
Like the Doctor, the Master had fled Gallifrey to explore the universe in a TARDIS (though a more sophisticated one than the Doctor's). Despite being a contemporary of the Doctor's, the Master burned through his regenerations much more quickly. The version of the Master encountered on Earth in the 1970s was in his thirteenth and final incarnation. The Master's presence was of concern to the Time Lords, who allowed the Doctor to try to bring the Master to justice. They also allowed the Doctor to briefly use his TARDIS to leave Earth and thwart the Master's plans on another world in the far future. The Doctor's success also inspired the Time Lords to allow him to leave Earth on other occasions (including a trip two thousand years into the future to the planet Peladon), indicating that they had become more convinced by the Doctor's argument that intervention was occasionally necessary.
Gallifrey then came under attack from an unexpected source: a black hole. With the planet's energy failing, they assigned the Doctor to investigate. With things growing more desperate, they allowed the Doctor to break the laws of time by joining forces with his first two incarnations to investigate the matter. They learned that Omega, the creator of the Eye of Harmony, had not been killed but had been blasted into an antimatter parallel universe, from where he plotted to take revenge on the Time Lords who had abandoned him. The Second and Third Doctors entered the antimatter universe and tricked Omega into apparently destroying himself, ending the threat. The Time Lords, saved, rescinded the Doctor's exile and allowed him to return to wandering through time and space.
From this point on, the Doctor's wanderings would be mostly the result of random chance or his own choice of destination, but the Time Lords would occasionally direct his adventures. During a confrontation with both the Master and the Daleks in the 26th Century, the Time Lords directed the TARDIS to the planet Spiridon, where a massive Dalek army was gathering, so the Doctor could destroy it.
Several years later, having regenerated into his fourth incarnation, the Doctor and his companions were intercepted by the Time Lords and sent to Skaro, the Dalek homeworld, in its distant past. The Time Lords informed the Doctor that they had discovered a possible future in which the Daleks had destroyed all other life in the universe. To avert this possibility, the Doctor was instructed to destroy the Daleks at the very moment of their creation. The Doctor failed, though his actions did change the timeline: the development of the Daleks was retarded by millennia and the Daleks' creator, Davros, survived. Whilst this seemingly averted the inevitable victory of the Daleks, it was also a declaration of war, and later historians would point to this as the very first shot of the conflict known as the Time War.
The Fourth Doctor visits Gallifrey.
Two years later, now travelling without a companion, the Doctor returned to Gallifrey and became embroiled in a complex plot to murder the President of the High Council. The Master was found to have been responsible. The Master had attempted a thirteenth regeneration, breaking the twelve-regeneration limit, and had paid the consequence by being reduced to a barely-living husk. The Doctor defeated the Master's plans, but the Master was able to escape. More than a year later, the Doctor returned to Gallifrey to help avert the invasion of the planet by the alien Vardans, initially by posing as their ally. However, the Vardans were providing cover for the real invaders, the Sontarans. Again the Doctor was able to defeat the invaders, this time by deploying Rassilon's formidable Demat Gun to annihilate them.
Many years later, after the Doctor had regenerated again, Omega returned and once again threatened Gallifrey with destruction. The Doctor defeated him once more. Shortly afterwards the Time Lords were alarmed when an unknown force breached the Doctor's timestream and transported his first five incarnations into the Death Zone on Gallifrey. The Time Lords themselves recruited the Master to help find out why. It turned out that the Doctor was being used as a canary in a mine, sent into the Death Zone to spring all the traps and open the way to the Tomb of Rassilon. The perpetrator was Borusa, President of the High Council. Approaching his final regeneration and death (unknown causes having resulted in him going through four incarnations in the same period the Doctor had gone through just one), Borusa yearned to discover Rassilon's secret of immortality which had been sealed in the tomb along with his body. The plan backfired when it was discovered that Rassilon had never died in the first place, instead going into lenghthy suspended animation. Rassilon turned Borusa to stone for his impertinence and returned to stasis, allowing the Doctor to go on his way. Shortly after this the Doctor was engaged in battle by the Daleks, who planned to send duplicates of the Doctor and his companions to Gallifrey to assassinate the High Council of Time Lords in retaliation for the Time Lords' attempt to wipe them out at the moment of their creation.
Several years later the Doctor was put on trial again by the Time Lords, though it turned out to be a manipulation by a future, potentially evil incarnation of the Doctor. During this 'trial' it became clear that corruption had started to seep into the fabric of Time Lord society, with some Time Lords being willing to blame the Doctor for one of their own interventions that had gone hideously wrong.
Not long after this, when he was in his seventh incarnation, the Doctor travelled to Earth in November 1963 to retrieve the Hand of Omega, the device Omega had used to create the Eye of Harmony and begin powering Time Lord civilisation. In actuality, the Doctor's plan was to trick the Daleks into destroying themselves, but was not expecting two separate and mutually hostile groups (the original, now 'renegade' Daleks and Davros's Imperial Dalek faction) to show up. In the end, Davros's Imperial Daleks assumed control of the Hand and sent it back to Skaro, planning to create for themselves a power source to rival the Time Lords'. Instead, the Hand, pre-programmed by the Doctor, caused Skaro's sun to go supernova, vapourising the entire star system and wiping out the Imperial Daleks in one go.
The result of these hostilities was that the Daleks of the far future, beyond the 201st Century, planned to make war upon the Time Lords. Aware of the growing tensions, President Romana chose to appease the Daleks by giving the Master to them. The Master had betrayed the Daleks on at least one occasion of cooperation, leading to them hating him almost as much as the Doctor. The Daleks exterminated the Master, but the Master had taken preventative action and enabled his essence to escape in a serpent-like form. The Doctor, shortly after regenerating into his eighth form, defeated the Master on Earth but was unable to return him to the Daleks for a final extermination, as the Master had toppled into the TARDIS's link to the Eye of Harmony. As a result, it appears that open warfare between the Daleks and the Time Lords broke out.
Gallifrey at the end of the Great Time War.
The Great Time War was a conflict unlike any other in history. The war raged on multiple battle fronts across thousands of worlds and multiple galaxies. Both sides invoked allies, but lesser species were not able to take part. Particularly affronted by this were the Sontarans, the only alien race to ever successfully (if extremely briefly) invade Gallifrey. Other powerful, higher races (such as the Eternals) fled this reality rather than stay and witness the conflict. Billions of sentient beings were killed and entire worlds and star systems were annihilated. Both sides were pushed into using their own war criminals as soldiers: the Daleks (although descended from the 'renegade' faction) used Davros's knowledge and experience, but he vanished early on in the conflict. The Time Lords retrieved the Master from the Eye of Harmony and gave him a fresh set of regenerations to help them. However, the fighting became so intense and the stakes so great that even the Master was terrified. He fled to the remotest future, the end of time itself, and transmogrified himself into a human, erasing all memories of the Time War and his old life.
Ultimately, the Time Lords re-awoke Rassilon. Rassilon agreed to take charge of the war, as he had done once before against the Great Vampires. More formidable and terrible weapons of war were unleashed: bowships from the old times and Battle TARDISes were deployed on a vast scale. The Daleks made use of other allies and weapons, such as the Cruciform and the Nightmare Child. The war escalated, until in its final days the Doctor estimated that millions of people were dying and being resurrected every day as time was written, rewritten, changed and undone. Rassilon decided to use the Ultimate Sanction, a force that would destroy the entire universe and allow the Time Lords to ascend to a higher form as beings of pure energy. The Doctor realised he could not allow this to happen. Deploying a weapon known as the Moment (which some claim - with doubtful veracity - was the old Demat Gun but made to work as a weapon of mass destruction, on a vast scale against millions of beings simultaneously), he obliterated Gallifrey and the Daleks' new homeworld both, along with their respective war fleets. Gallifrey burned and billions died. Whatever the Doctor did was so horrendous that the entire Time War became time-locked, sealed away from the rest of the universe and impenetrable to time travellers from any direction. The Doctor himself paid with his life, undergoing regeneration. However, it is not known how the Doctor alone was able to escape from the time lock into the outside universe.
At the moment of annihilation, the Time Lords manipulated the Master (whom they knew had fled) into pursuing a course of action that would ultimately lead to their salvation, with Gallifrey being pulled out of the Time Lock into the vicinity of Earth so they could use the Ultimate Sanction. The Tenth Doctor and the Master defeated Rassilon and the Time Lords, returning them to the time lock and their annihilation in the Moment. The Master also apparently perished at this moment and the Doctor was also killed, undergoing regeneration into his eleventh form.
It is generally held that the Eighth Doctor fought in the bulk of the Time War and was the Doctor who was killed at its conclusion, undergoing regeneration into the Ninth. However, recent rumours claim that the Doctor had another form between his eighth and ninth selves who carried out the Moment, an act of desperation and barbarism on such a scale that it went against everything the Doctor stood for despite the overwhelming circumstances. The truth of this claim remains to be seen.
Regardless, the Time Lords are now considered to be extinct. The elimination of the Time Lords has seen those aspects of time travel that they regulated, such as interdimensional travel, become much more dangerous and difficult. Other races that did not apparently possess time travel (possibly due to Time Lord interference) subsequently did: humans in the 51st Century developed primitive time travel technology whilst prior to the Time War it appears that humanity never mastered the technology. Damage to the timeline became more dangerous without the Time Lords being around to help fix it. The Doctor became the last of the Time Lords.
Timothy Dalton, David Tennant and John Simm during the filming of The End of Time, 2009.
Behind the Scenes
When he first appeared on-screen in 1963, the Doctor was identified as an alien, travelling from world to world with his granddaughter Susan. Little more information was given out, and some of what was revealed was contradictory. In truth, the writers and producers of Doctor Who didn't know and didn't care particularly about the Doctor's origins, feeling they would not be a major focal point of the show. However, the 1965 story The Time Meddler did introduce another member of the Doctor's own race, the Monk, equipped with his own TARDIS, and the possibilities of revisiting the Doctor's origins became clearer.
At the end of the sixth season in 1969, it was planned that the show would switch to being made in colour. Patrick Troughton was also expressing a desire to move on. The producers decided that the show would undergo a total format reboot, arguably the first of its kind in the show's history (the later serial The Leisure Hive in 1981 would also feature a reboot and update of the way the show was produced, although of lesser magnitude). As well as moving to colour there would be a total replacement of the cast: a new Doctor and companion would come in simultaneously and there would be other recurring cast members. To save money (as the move to colour was expensive) the show would also be set on present-day Earth with no visits to alien worlds (which were always expensive to shoot but ended up looking shoddy). There would also be more focus on action and contemporary issues (such as nuclear power, the environment and the Space Race). To explain the massive shake-up, the producers decided that the Doctor's past would catch up with him. Building on the earlier hints that the Doctor had stolen the TARDIS to see the universe, it was decided that he was on the run, a fugitive and criminal, and his people wanted him back. His people were named the 'Time Lords' and would appear in the Second Doctor's final story, The War Games.
From this point onwards, the Time Lords would remain an ongoing part of the Doctor Who storyline and mythos. They briefly reappeared during the Third Doctor's run, along with Omega, but it was Robert Holmes's The Deadly Assassin in 1977 which firmly established a lot of the background and lore behind them, including mentions of the Eye of Harmony, Rassilon and the different chapters. Robert Holmes was also the writer responsible for naming Gallifrey, which he did in 1973's The Time Warrior (rather oddly, after years of ducking the issue, the Doctor just casually reveals the name of his homeworld to the first Sontaran to appear on the show). Holmes also established the twelve-regeneration limit for Time Lords. Despite establishing a lot of the backstory and lore, Holmes didn't play much more of a role in their development (though he did introduce the idea of the Rassilon Imprimatur in The Two Doctors). Instead other writers would develop the Time Lords rather roughly and ad hoc as they continued to reappear.
The biggest problem with the Time Lords is that they provided too much of a safety net for the Doctor to fall back on, especially once he was back on friendly terms with them (and indeed serving as titular President of the High Council, as he did from The Five Doctors through the end of the series). There were also problems finding interesting things for them to do: the Doctor being put on trial by them twice shows some a lack of imagination in how to handle them on the show. When Russell T. Davies resurrected the show in 2005, his answer was to simply wipe them out in a mutual war of annihilation against the Daleks. Davies even used some of the events from the original series to justify the conflict: the Time Lords trying to wipe out the Daleks at the moment of their creation in 1975's Genesis of the Daleks; the Daleks trying to send android duplicates of the Doctor and his companions to wipe out the High Council in 1984's Resurrection of the Daleks; the Doctor blowing up Skaro in 1988's Remembrance of the Daleks; and the Time Lords handing the Master over to the Daleks in the 1996 TV movie.
The removal of the Time Lords from the mythology and making the Doctor the last of his race had interesting dramatic ramifications for the series and the character of the Doctor. The true course of the Time War would be teased out over many episodes until it was eventually possible to assemble a very rough idea of the course of the war. However, Davies also used the Time War as an excuse to explain away any potential continuity errors within the show, since what happened in the prior run of the series could have been changed or undone by the Time War. Of course, Davies would not be able to resist bringing back first the Master and later on the Time Lords themselves for David Tennant's final story (complete with Timothy Dalton playing Rassilon!).
Fans continue to ponder if the Time Lords will be restored at some point in the future, when the show needs another big shake-up, and that is certainly possible (Dalek Caan penetrating the time lock to save Davros, even at the cost of its own sanity, shows there is a way of doing this). For now, the Time Lords with their unfeasibly big collars are gone and the show has benefited from their absence so far, making the Doctor a more important and solitary figure as a result.
The War Games (1969)
The Three Doctors (1973)
The Deadly Assassin (1977)
The Invasion of Time (1978)
Arc of Infinity (1982)
The Five Doctors (1983)
The Trial of a Time Lord (1986)
The End of Time (2009-10)
Time Lord Terminology
Bowships: Immense Time Lord spacecraft which fired huge projectile weapons. Necessary to kill the Great Vampires. Re-used in the Time War.
Capitol, The: Largest city of the Time Lords on Gallifrey.
Demat Gun: Weapon which obliterates the target and removes it from the space/time continuum altogether.
Eye of Harmony: Link to the black hole used to power Time Lord civilisation, including all TARDISes. Sometimes used to refer to the black hole itself and the TARDIS's power source.
Gallifrey: Homeworld of the Time Lords.
Great Vampires: Alien species who fought an early war against the Time Lords. Defeated by Rassilon using bowships.
Hand of Omega, The: Stellar manipulation device, capable of collapsing stars. Used by Omega to create the Eye of Harmony. Used by the Doctor to destroy the Dalek homeworld.
High Council: The ruling body of the Time Lords, headed by an elected President.
Moment, The: Weapon of mass destruction. Used by the Doctor to end the Time War.
Omega: Gallifreyan scientist, creator of the Eye of Harmony.
Rassilon: Gallifreyan scientist and later politician, first President of the High Council. Omega's contemporary and partner. Founder of Time Lord civilisation. Discovered immortality and entered stasis for millennia. Awoken to fight in the Time War.
Rassilon Imprimatur: A form of genetic engineering which allows Time Lords to travel through time and achieve a symbiotic link with their TARDISes. Theorised to also enable regeneration.
Regeneration: Process by which a Time Lord undergoes total body rejeuvenation, returning every cell to a healthy state and retaining memories but in the process creating a new consciousness and personality. Each Time Lord can regenerate up to twelve times before dying, with each body living for seven or so centuries.
TARDIS: Time and Relative Dimension in Space. A vehicle capable of space/time travel.
Time War or Last Great Time War: Conflict in which the Time Lords and Daleks fought to their mutual destruction.