Outcast

In one of the infinite parallel universes of "possible space", (COMIC: Fire and Brimstone) the Outcasts were a sect of Gallifreyans distinct from the Time Lords. While the Time Lords kept to the Domed City of Gallifrey, the Outcasts dwelled in the forbidden deserts outside the City's bounds.

Nature
Although they cultivated a reputation of senseless savagery entirely separate from the Time Lords' ways, the Outcasts were actually a secret order founded by Rassilon himself to guard the secrets of his Tomb, a vast underground structure built into a mountain. Their numbers were occasionally increased by Time Lords, or Time Lord progeny, who were banished from the Domed City. When Barusa told his grandson the Doctor of his secret half-human parentage, he explained that if it had been known that the Doctor was not a full-blooded Time Lord by birth, he would surely have been barred from becoming a Time Lord, and instead sent out to be raised as an Outcast. (PROSE: The Chronicles of Doctor Who?)

History
For thousands of years, the Outcasts jealously guarded the Tomb of Rassilon.

Eventually, after the Doctor was banished from the Domed City, they found him nearly dead in front of the gigantic carved cliff-face that marked the location of the Tomb, having wandered the desert for weeks. They took him in and nursed him back to health, sensing that he was the prophesied one for whom one of the artefacts in the Tomb, the Scrolls of Rassilon, were destined. After he was well again, they showed the Doctor the secret passageway through a cave system that allowed entry into the Tomb. (PROSE: The Chronicles of Doctor Who?)