Aliases of the Master

Like the Doctor, the renegade Time Lord known as the Master used many aliases. However, while the Doctor used false names on a fairly ad hoc basis to avoid awkward questions, the Master usually adopted them in order to further whatever scheme they were embarked upon at the time.

"The Master" was itself an alias. He chose this name, as the First Doctor did his, while attending the Academy. (TV: The Sound of Drums; AUDIO: The Destination Wars)

Behind the scenes

 * During Anthony Ainley's tenure as the Master, pseudonyms made from anagrams of "Tony Ainley" were often used in the credits — both on-screen and in Radio Times — for the Master's disguises, such as Neil Toynay for the Portreeve in Castrovalva.
 * Another, craftier pseudonym was used in Radio Times for The King's Demons, when Sir Gilles was listed as being played by "James Stoker" — an anagram of "Master's Joke".
 * In Sympathy for the Devil, Mark Gatiss, who voiced an alternate version of the Master, is credited as "Sam Kisgart", an anagram of the actor's name. When this incarnation of the Master returned in The New Adventures of Bernice Summerfield, Gatiss was again credited as Kisgart but the joke was dropped out for later user stories.
 * Professor Stream in The Hollows of Time was originally intended to be a pseudonym of the Master, but copyright restrictions prevented them from making this explicit in the story. "Stream", like "Tremas", is an acronym of "Master". The story is listed as a Master one on the Big Finish website.