In the Academy, the members of the Deca questioned and debated the profound wisdoms and Ancient Covenants of Gallifrey. The Deca included the First Doctor, the Master, the Rani, Mortimus, Drax, (PROSE: The Quantum Archangel) Vansell, (AUDIO: The Rani Elite) and four others. (PROSE: The Quantum Archangel) The Fifth Doctor dreamt that other members were Rallon, Jelpax, Millennia, and Magnus.
Of these, Millennia and Rallon were made a part of the Celestial Toyroom, Jelpax became the Coordinator of the APC Net, (PROSE: Divided Loyalties) Vansell became head of the Celestial Intervention Agency, (AUDIO: The Sirens of Time) and the remaining six became renegade Time Lords.
The Fifth Doctor dreamed that the group represented the top rank of students in their class, (PROSE: Divided Loyalties) although the First Doctor was said to have not excelled academically. (TV: The Ribos Operation)