The cult of Rassilon the Vampire was a following, kept alive by tiny bands of heretics on Gallifrey. They kept vampire shrines in the ducts and service ways of the Capitol where none of the workers went.
They believed that Rassilon allowed himself to be bitten by the Great Vampire and was thus a vampire towards the end of his life. The Time Lady Ruath was a member of this cult, possessing the Sigil ring and learning of the cult's prophesies detailing the coming of the Vampire Messiah. One of their books was made out of human flesh and a literal spine. (PROSE: Goth Opera)