Astrolabus

Astrolabus was a renegade Time Lord who stole the Book of the Old Time, as well as the treasures of a dozen worlds.

Biography
The Doctor and Frobisher first encountered him when they found out he stole the star-charts of the Voyager. (DWM: Voyager)

As Professor Astro Labus, he set himself up as president of the Zyglot trust, while as the swami Astral Arbus, he employed Akkers to capture Zyglots. When the Doctor and Frobisher caught up with him, he pulled the Whifferdill with him into his cabinet. (DWM: Polly the Glot)

A book known as the Insidium of Astrolabus was among the evil or arcane works which were kept in the Master's Tardis library. (PDA: The Quantum Archangel)