The Deca

The Deca was a group of young rebellious Gallifreyans at the Academy, which included the Doctor. Apart from the Doctor, Azmael, Drax, Koschei (later known as the Master), Magnus (later the War Chief), Mortimus (later the Monk) and Ushas, later known as the Rani, made up the Deca.

The Deca finished when the Doctor betrayed the group by leaving Gallifrey. In time, each member of the group would choose a lifestyle as a renegade across space and time. (PDA: Divided Loyalties)