C is for... Castellan

The Doctor had encountered two other holders of this post on Gallifrey before he met this unnamed individual. The Castellan was a senior Time Lord, responsible for internal security. He commanded the Chancellery Guards. This Castellan held a seat on the High Council, and was one of its key members. At the same time that he was investigating the apparently accidental death of a Time Lord technician, the Time Lords became aware that an entity from the universe of Anti-Matter was attempting to break into this universe by bonding itself physically to the Doctor. The Castellan had the TARDIS recalled to Gallifrey, materialising it in a security area. A humourless and obsessive man, he failed to heed warnings by a friend of the Doctor's - Damon - that might point towards a traitor at work. He pursued the Doctor ruthlessly. When the Doctor was captured and sentenced to vapourisation the Castellan harboured doubts, and ordered Captain Maxil of the Chancellery Guards to investigate the execution. A fellow member of the High Council - Hedin - was the traitor, seeking to bring Omega back from his long exile. Hedin manufactured evidence that made President Borusa look like he was in league with the Doctor. The Castellan was prepared to shoot down the Doctor when he went to arrest Borusa, but Hedin intervened and was killed, as he knew Omega needed the Doctor alive.

Later, when the Doctor was taken out of time in all of his regenerations and deposited in the Death Zone on Gallifrey, the Castellan was once again part of the inner circle of the Council. This was the work of Borusa. Knowing of the animosity felt by the Castellan towards the Doctor, he made the perfect scapegoat to throw attention away from himself. He arranged for the forbidden Black Scrolls of Rassilon to be found amongst the Castellan's effects and ordered his arrest - authorising use of the Mind Probe to interrogate him. He then engineered his murder, employing a Chancellery Guard Captain to shoot him down in a faked escape bid.

Played by: Paul Jerricho. Appearances: Arc of Infinity and The Five Doctors (1983).

• A Castellan is the governor of a castle.