The Master (Exile)
The Master is a Timelord from the planet Gallifrey
The Master has used many fake names, including Roger, Peter, Geoffrey, Tony, Eric, Robert and Sam.(Exile (audio story))
Roger, Peter, Geoffrey, Tony, Eric, Robert and Sam all refer to the actors that played the Master, like Roger Delgado, Peter Pratt, Geoffrey Beevers, Anthony Ainley, Eric Roberts, and Sam Kisgart.