High Court of the Time Lords

By some accounts, the High Court of the Time Lords was a powerful Time Lord institution which held the Doctor's first trial. (PROSE: The Trial of Doctor Who, World Game) Other sources would suggest other organisations filled this role. (PROSE: Doctor Who and the Doomsday Weapon, Doctor Who and the Terror of the Autons, et al.)

Drax once remarked to the Fourth Doctor that he had heard about the High Court exiling the Doctor to Earth. (PROSE: Doctor Who and the Armageddon Factor)

The Sixth Doctor once made reference to the High Courts of Gallifrey. (PROSE: Revelation of the Daleks)