Borusa

Borusa was a notable and ultimately tragic figure in the history of the Time Lords of Gallifrey, and a very important figure in the life of the Doctor. At various points in his life, he assumed the ranks of Lord President, Cardinal and Chancellor of Gallifrey.

Early life and career

Borusa held the degree of a jurist and was a tutor to the First Doctor. Among the other subjects, he taught mind shielding. He wrote a paper on reason, which the Doctor had read. Like the Doctor, Borusa was a member of the Prydonian Chapter.

Involvement with the Master

When the Fourth Doctor returned to Gallifrey to defeat the Master, Borusa was Lord Cardinal on the High Council. He set about "adjusting the truth" in the wake of these events, portraying the late Chancellor Goth not as the Master's ally, but as a hero who had given his life to stop the Master. Unsurprisingly, the Doctor was appalled, and was more than happy to leave Gallifrey in return for the charges against him (of assassinating the President) being dropped.

During the Sontaran invasion

After the Doctor left Gallifrey again, Borusa officially became Lord Chancellor — apparently illegally — and at some point regenerated. The Doctor returned to Gallifrey briefly to officially take up the post of Lord President — which he had nominated for as a legal ploy during his previous trial, and which he automatically held after rival candidate Goth had died — as part of a strategy to defeat the Vardans. Once they and their puppet masters, the Sontarans, had been seen off, the Doctor departed, again leaving Gallifrey in Borusa's hands.

Career as Lord President

Some time before the second crisis involving Omega, Borusa was inducted officially as Lord President, and regenerated again. Councillor Hedin left evidence of his own crimes that made it seem that Borusa was the criminal. Borusa corrected the Time Lords, revealing Hedin's wrongdoing, and hoped that Omega would find peace after the Fifth Doctor sent him back to the antimatter universe.

Descending into madness

Regenerating yet again — with his stubborn streak apparently enhanced in the process — Borusa used his presidential powers to investigate the legacy of Rassilon from the Dark Time of Gallifrey. He pursued access to the Tomb of Rassilon, where he believed he would find the secret of immortality, ruling Gallifrey forever as "President Eternal". To this end, he reactivated the ancient Time Scoop, and revived the long-forbidden war games between captured representatives of various species in the Death Zone surrounding the Tomb.

Borusa summoned all of the Doctor's previous incarnations to the Zone (though the Fourth Doctor ended up becoming trapped in the Time Vortex), convinced that at least one would gain entry to the Tomb. Once three of them had, he tricked them into deactivating the forcefield blocking transmat access to the Tomb. After reaching the Tomb, however, he found that the promised immortality was a trap set by Rassilon to capture power-mongers such as himself. Borusa was condemned, like others before him, to live his "immortal" life trapped within a sarcophagus.

Biography from the TARDIS Data Core article, licensed under CC-BY-SA