Spandrell

Spandrell was Castellan of the Chancellery Guard on Gallifrey for many years. He was succeeded by Castellan Kelner. Spandrell was Castellan during the President's assassination, and led the subsequent investigation into the attack. He was very sceptical of the Fourth Doctor at first, but ended up becoming his ally in the unmasking of Chancellor Goth as the President's murderer. (DW: The Deadly Assassin)

When Spandrell was Castellan, it was rare for the office-holder to deal with criminal offences by Time Lords; his duties more often brought him into contact with "more plebeian classes" (presumably non-Time Lord Gallifreyans. (DW: The Deadly Assassin)

Spandrell was persuaded to come out of retirement to serve under Lord President Flavia. (NA Blood Harvest, NA: Happy Endings, EDA: The Eight Doctors)