Morbius

Morbius of House Dvora was a high-ranking Time Lord whose career was the first in milennia to dramatically alter Gallifrey's relationship to the wider universe, briefly moving the world's policy away from observation and manipulation of external affairs and instead towards brutal restructuring of the universe to suit Gallifrey's best interests (DW:The Brain of Morbius, FP:The Book of the War). The Fifth Doctor became embroilled in the chaos that resulted (PDA:''Warmonger). His career ended in ignominy and destruction, and he escaped a sentence of death only by means of a secret brain transplant, subsequent to which he encountered the Fourth Doctor (DW:''The Brain of Morbius).

The Imperator Crisis
Morbius' ambition led him to become the head of the High Council, where his warlike nature led him to urge the Time Lords toward a policy of conquest (DW: The Brain of Morbius), demanding the Laws of Time and structure of the universe be redrawn to better suit Gallifrey's needs (FP: The Book of the War).

While still based on Gallifrey he formed a personal army composed of both dedicated followers and mercenaries from other species. He promised these followers the secrets of time travel and immortality (DW: The Brain of Morbius) although withheld from them true admission into his House (FP: The Book of the War).

When the Time Lords, spurred by the Order of the Weal (FP: The Book of the War), eventually denounced him, he and his followers abandoned Gallifrey and began an assault on the cultures of the external universe (DW: The Brain of Morbius).

As Gallifrey's society struggled to understand these inconceivable events, the long-term cultural changes brought about would include the increased influence of the Celestial Intervention Agency and the founding of House Paradox (FP: The Book of the War).

War with The Alliance
Unsure how to respond to the physical campaign of conquest Morbius was waging against the universe (FP: The Book of the War) the Time Lords eventually chose to fight the war by proxy (PDA: Warmonger).

The Fifth Doctor, who had travelled into Gallifrey's past, was appointed 'Supreme Coordinator of the Alliance Battle Fleet' and directed an unlikely army of Humans, Draconians, Cybermen, Ogrons, Ice Warriors and Sontarans against Morbius (PDA: Warmonger).

Planets involved in the conflict included Fangoria, Romark, Darkeen, Martak and Freedonia which provided troops for Morbius, and Sylvana, Zandir, Tanith and Electra which fell to him (PDA: Warmonger).

The Alliance eventually defeated Morbius on Karn with the assistance of the Sisterhood and brought to trial, although the verdict had been decided in advance (PDA: Warmonger). The sentence of death by public and ceremonial disintegration was partly a panicked attempt by the Time Lords to caution the universe at large against opposing them (FP: The Book of the War).

His body was indeed destroyed, with Sisterhood leader Maren among those attending. However, Morbius escaped death when one of his followers, the human surgeon Doctor Mehendri Solon, secretly removed the Gallifreyan criminal's brain before his disintegration.

Taking the brain, Solon went into hiding on Karn, where he began planning to build a new body for Morbius. The Sisterhood's means of defending the Elixir of Life was to cause nearby spacecraft to crash, which provided a regular supply of corpses from which Solon could scavenge body parts for this project (DW: The Brain of Morbius).

Morbius' Brain
Landing on Karn, The Doctor and Sarah Jane Smith stumbled upon Solon's castle just as Morbius' new body neared completion. The Doctor recognized Morbius' telepathic brain pattern despite, at this point in his timeline, not having previously met Morbius in person.

Morbius's new body was horrifyingly grotesque, leading the Doctor to mock him as "Chop Suey, the Galactic Emperor!" but Solon's ability to merge alien tissues offered some advantages, including lungs from a Birastrop capable of withstanding cyanide. Other parts of Morbius' body included a human left hand from Solon's unknowing assistant Condo, a giant lobster-like right hand, and a humanoid torso.

Yet the new body lacked one important element, a suitable vessel for carrying the unique and delicate properties of a Time Lord brain. The head of another Time Lord was required, but when plans to use the Doctor's head failed and the container that had been so far holding the brain was spilled, Solon resorted to an unproven, experimental braincase which included two stalk-like eyes.

This braincase was prone to developing a static charge, a weakness the Doctor exploited by challenging Morbius to a Time Lord mindbending contest. It is not at all clear who won the contest, but it was costly for both Gallifreyans. The Doctor collapsed from the strain, and Morbius' brain appeared to be damaged by a static shock.

There exists some ambiguity surrounding the faces which appear during the mind bending contest.

After the battle, Morbius appeared to be left in a dazed, animalistic state. He did not speak again, and only uttered seemingly agonized sounds of anger and pain. Leaving Solon's castle, he was chased by the Sisterhood over a cliff, where he was apparently killed (DW: The Brain of Morbius).