The Eleven

The Eleven was the main alias used by a Time Lord criminal in their eleventh incarnation. They had a mental illness called regenerative dissonance, which manifested as their previous incarnations' personalities arguing in their mind. Each incarnation went by a sequential number.

The One
The One once worked in the Panopticon Archive, where he found information about a prototype stellar manipulator. He had a seat on the High Council, although this was explained as a result of the Council promoting him to the position when various other members were away on other business and a certain number of votes were required for particular motions to be passed. He later left Gallifrey and became a criminal.

During her meeting with the Eleven, Kiani hinted that the One had a different name before he became a criminal, but the Eleven insisted on calling him "the One." (AUDIO: The Eleven, The Satanic Mill)

The Two
The Two boasted that his "nose was particularly good at sniffing out traitors." Within the Eleven, he exposed Volstrom's betrayal of Padrac as an agent of Ollistra. (AUDIO: Songs of Love)

The Three
The Three, as noted by the Eighth Doctor, was one of the personalities more willing to kill. (AUDIO: The Eleven, Companion Piece) After finding out that Bliss was indeed a companion of the Doctor and that she wouldn't be killed by the Nine, the Three complained about it, and was told that one can't always gat what they want. (AUDIO: Companion Piece)

The Four
The Four was described by the Eighth Doctor as "weaker than the Eleven". (AUDIO: Stop the Clock)

Right after the Nine kidnapped Liv and Helen, the Four claimed it was his plan to make disguise the Clocksmith's TARDIS as a police box to make it look like the Doctor's.

He explained to River Song that the companions of the Doctor kidnapped by the Nine couldn't escape because the prisoner cells of the prison were shifted fowards in time. (AUDIO: Companion Piece)

The Five
The Five commented on Volstrom's new nose shortly after her regeneration. (AUDIO: The Side of the Angels) The Five boasted he was a formidable opponent who was capable of killing everyone even when he was incarcerated within the Eleven when he had been caught by the Time Lords. The Eleven rebuked him for giving the game away. (AUDIO: Stop the Clock)

The Six
The Six was by far the most violent of the Eleven's personalities, and also one of the most unstable. He would often try to get the Eleven to butcher his way through a situation, regardless of whether the victims could be of use. (AUDIO: The Eleven, Companion Piece)

When Liv called the Nine a psychopath, he corrected her, saying that he was a kleptomaniac, and the psychopath was "three regenerations back".

Angered by River Song's plan of escaping, the Nine considered letting the Six "off the leash". He found the Nine's torture of River, Liv, Helen, Charley and Bliss to be "fun". (AUDIO: Companion Piece)

The Seven
The Seven was known for being rude and abrasive. Indeed, the Nine thought that him congratulating the Eleven was rare. He was also the more scientifically inclined incarnation. He was used by the Eleven to portray a scientific advisor. (AUDIO: World of Damnation, Sweet Salvation)

When the Nine was aiming for kidnapping all of the Doctor's companions, River Song told him to retrieve Katarina's dead body, as that would be the only way to get a "complete collection". In fact, her body was being guarded by a younger version of River, who confronted the Time Lord, giving the older River a chance at escaping. It was the Seven who realised her plan and warned his future self to go back to the TARDIS. (AUDIO: Companion Piece)

The Eight
The Eight was an aberration compared to his other incarnations, attempting to be a "good man". Using meditation, he was able to suppress the voices of his previous incarnations. He became involved with the Time Lords' (and his) future, attempting to stop the Eighth Doctor from assembling the Doomsday Chronometer.

Posing as "Father Octavian", he linked minds with the Doctor and "Sister Cantica" to stop the Clocksmith. After he was killed by the Clocksmith, the Eight retreated into the Doctor's TARDIS and regenerated. When the regeneration occurred, he heard the voices of his previous selves, who urged him to regenerate and also taunted him for not being one of them, while the Six wanted to return so he could kill people again. (AUDIO: The Eighth Piece / The Doomsday Chronometer)

While the Nine was being chased by the Chancellery Guard, the Eight suggested to him that he surrended, a suggestion quickly shut down by their current incarnation. (AUDIO: Companion Piece)

As a thriving persona inside the Eleven's consciousness, he successfully took control of his physical body and told the Doctor about Padrac's plans to use the Resonance Engine as a means to amplify Caleera's powers. (AUDIO: Stop the Clock)

While discussing her previous selves, the Twelve thought the Doctor was being unfair on the Eight, whom she described as "sweetness itself", which the Doctor conceded by describing him as "the exception that proved the rule". (AUDIO: Planet of the Ogrons)

The Nine
After regenerating, the Nine initially claimed to be a new incarnation of the Doctor to Helen Sinclair and Liv Chenka. Rather than trying to be a "good man" like his predecessor, the Nine was motivated by kleptomanic greed. Helen and Liv helped him to rob the archive on Gallifrey, but he abandoned Liv when she became suspicious of his erratic and condescending behaviour. He took Helen hostage and brought her to the Crucible of Souls. He attempted to use the Crucible to gain immortality and exorcise his previous incarnations. After being thwarted by the Eighth Doctor, the Nine stole the Clocksmith's TARDIS and ran away. (AUDIO: The Crucible of Souls) He ran into River Song, whom he kidnapped. He then decided to get a complete collection of the Doctor's companions, torturing River in order to find out their names and locations. After collecting them, they were placed in a prison. After being defeated by River, Liv, Helen, Bliss and Charley, the Nine was left behind in the prison. (AUDIO: Companion Piece)

The Doctor later described this incarnation to Bliss as a kleptomaniac. The Twelve used the Nine's expertise to break into a Dalek base. (AUDIO: Planet of the Ogrons)

The Ten
The Ten was known for his skills in hypnotism. He once killed a squad of Gallifreyan soldiers on Dalgar by hypnotising the first officer to kill the commander, then the second officer to the first officer, and so on. The Ten let Tessno survive the incident so that she could tell Gallifrey about what he had done. (AUDIO: Stop the Clock)

The Eleven
The Eleven was originally captured by the Seventh Doctor (AUDIO: The Eleven) and Rasmus (AUDIO: Desperate Measures) and imprisoned on Gallifrey. Later he managed to escape and steal a TARDIS. The Eighth Doctor was brought in to find him. The Eleven installed himself as Lord President by an ancient edict, as he created a state of emergency while the President was off-world. He used the Sash of Rassilon to freeze the Time Lords. (AUDIO: The Eleven)

The Eleven hired Fortuna and Cleaver to bring the Doctor to him. (AUDIO: The Galileo Trap)

The Eleven found the prototype stellar manipulator and planned to use the death of a Time Lord to activate it and destroy the solar system. He captured the Doctor for these means. The Eleven's plans were prevented by an unknown force, and the Doctor's sonic screwdriver signalled for his TARDIS to land nearby, allowing him to escape. (AUDIO: The Satanic Mill)

The Eleven was once interviewed by Caleera for the archives, as he knew she was special. He convinced her to amplify her powers for his plans. (AUDIO: Scenes From Her Life) He then came to Syra as part of his plans with Caleera. He planned a trap in the mines to kill the Doctor. He also tried to kill Liv in the mines, but River Song stopped him. He wanted to use Caleera to destroy planets. (AUDIO: The Sonomancer) He sabotaged Livia's TARDIS before he went to the Crucible of Souls and found out that Veklin had abandoned it. (AUDIO: Songs of Love)

The Eleven later followed the Doctor and his companions to 1970s New York to track Ollistra and destroy the remaining Time Lords who were against Padrac's plans. There, he met and found out about the alliance of Ollistra and the Weeping Angels. He later manipulated the Monk and the Weeping Angels to do his bidding, helped by the Monk's desire to save his own life and used the latter to take the Time Lords who were hiding in New York as hostages. After a heated argument, he pushed Ollistra from the top of the building and fought the Doctor. Then, it was revealed that Padrac was just using the Eleven as a pawn, causing a commotion between his past incarnations. This pushed the Eleven to use his Time Ring to go back to Gallifrey and see the truth. The Doctor used this as his chance to follow him to Gallifrey. (AUDIO: The Side of the Angels)

The Eleven later found out that he could not enter the Capitol, and was found by Tessno outside the city. The latter almost killed him due to a personal grudge, but the Doctor stopped her from doing so. The Eleven was later brought in to the headquarters of the Opposition. Tessno was asked to lock him inside a room, where he provoked Tessno by using her grudge against her. Tessno released the Eleven to challenge him, but he killed her instead and escaped. He later brought Helen as a hostage and rode a Battle TARDIS to counter the plan of the Doctor to disguise as the Eleven to infiltrate Padrac's headquarters. When Caleera gave Helen the power of the Sonomancer, he was held down by Helen as the latter used the Battle TARDIS to destroy the Resonance Engine. (AUDIO: Stop the Clock)

The Battle TARDIS crashlanded on Rykerzon, and Helen and the Eleven were taken as prisoners. During that time, Helen cared for the Eleven and tried to help him control his condition, suppress the voices of his other incarnations. The Eleven pretended to be receptive, even calling Helen his "saviour", but it was all an act, since he wanted to use her new abilities from the Sonomancer in his plans, and link her with the psychic spider. When the Doctor and Liv arrived looking for Helen, she was thrilled to see them again, despite the Doctor being sceptical of her. Eventually, the Eleven joined with the Kandyman to take over Colony 23, a plan which was then stopped by the Doctor, Liv and Helen. He got away and became terrified of the Ravenous' arrival, something he saw whilst being linked to the psychic spider. (AUDIO: World of Damnation, Sweet Salvation)

The Eleven was able to kill Jaxa and steal her TARDIS, but the ship was somehow attacked by one of the Ravenous, forcing him to send a distress call to the Doctor. When the Doctor traced the call back to its source, the Eleven explained what was on Jaxa's ship, but subsequently stole the Doctor's TARDIS while the Doctor and Helen were trying to save the trapped Liv from the Ravenous, leaving them on Jaxa's dying TARDIS. (AUDIO: Seizure)

The Twelve
The Eleven later regenerated into a female body. The Twelve had a much better control of the incarnations within her mind, due to a neural inhibitor given to her by the Time Lords, although she also considered herself as possessing the firm hand necessary to keep them all in line. She was assigned on a mission by the High Council to help the Eighth Doctor investigate the origins of an Ogron which declared itself to also be the Doctor.

During this time, she proved her control over her previous selves by summoning the Nine's personality when she and the Doctor needed to break into the Daleks' base. (AUDIO: Planet of the Ogrons)

She was captured by the Daleks, along with the Doctor and Bliss and taken to a facility with her memory suppressed. She was given the name "Pi Gamma" by Bliss. Without her neural inhibitor, she had to work harder to keep her other incarnations suppressed. She attempted to break out of the facility, with her previous incarnations prodding and goading her, forcing her to develop a means of disrupting the transmat technology using the cybernetic components of another prisoner. (AUDIO: In the Garden of Death)

After the encounter with the Daleks on Uzmal, Cardinal Ollistra had the Twelve put into stasis. (AUDIO: Jonah)

Behind the scenes
, no name has been given in-narrative for this Time Lord in general (only for each of their incarnations). However, John Dorney, who regularly wrote stories featuring the character, has expressed fondness for the name "the Collective".