Maxil

Zealous and humourless, Commander Maxil was a member of the Gallifreyan Chancellery Guard.

Biography
Like all Time Lords, Maxil was taken from her family at the age of eight for the selection process in the Drylands. Staring into the Untempered Schism as part of a Time Lord initiation rite, Maxil was inspired by what she saw in the Schism. (PROSE: A Brief History of Time Lords)

Later in life, Maxil, now in a male incarnation, was working for the Gallifreyan Chancellery Guard, where he had attained the rank of Commander. During this time, he stunned the Fifth Doctor with a staser blast and confined him in a cell under the Capitol to await the judgment of Lord President Borusa and the High Council of the Time Lords. He also planted a listening device in the Doctor's TARDIS. (TV: Arc of Infinity)

He was promoted to Castellan shortly after the supposed death of Andred. (AUDIO: Lies, Imperiatrix) After siding with Pandora and Inquisitor Darkel in the Gallifreyan Civil War, he was demoted back to Commander. (AUDIO: Appropriation)

Behind the scenes

 * Maxil was portrayed by Colin Baker, who later became the Sixth Doctor. Maxil was to have appeared in The Five Doctors but was dropped due to Baker being unavailable. A myth later arose that this was as a result of Baker being chosen to succeed Peter Davison as the Doctor; however, in fact, Baker wasn't offered the role of the Sixth Doctor until June 1983, months after the Five Doctors was filmed.
 * Maxil shoots the Fifth Doctor at one point during Arc of Infinity. As a result, Baker has often joked that he gained the role of the Doctor by shooting the incumbent.
 * Colin Baker has said he made the suggestion that, in The Mysterious Planet, Commander Maxil should have arrested the Doctor and taken him into the courtroom on Space Station Zenobia.
 * This was the first time that a future actor to play a Doctor was involved in an earlier production on screen. Baker would be succeeded in this regard by Peter Capaldi. Prior to being cast as the Twelfth Doctor in 2013, Capaldi played both Lobus Caecilius in The Fires of Pompeii in 2008 and John Frobisher in Torchwood: Children of Earth in 2009. Furthermore, David Tennant participated in several Doctor Who audio dramas for Big Finish Productions (the first being Colditz) and had a minor voice role in Scream of the Shalka before being cast as the Tenth Doctor.
 * Justin Richards had suggested that, in The Inquiry, Maxil should be revealed as the Sixth Doctor, who chose to remain on Gallifrey in the timeline in which Minyos was not destroyed by the time bomb. However, Gary Russell felt that this development would be too complicated.