Derek Jacobi

Sir Derek Jacobi (born 22nd October 1938) is a British actor, knighted in 1994 for his services to theatre.

He has performed in three different media for Doctor Who. Undoubtedly most associated with the character of the Master, he played two different incarnations of that Time Lord. (DW: Utopia, WC: Scream of the Shalka) He also portrayed Martin Bennister, an aging would-be television writer whose life was apparently ruined by his inability to sell a series called Doctor Who. (DWU: Deadline)

According to an interview he gave for Doctor Who Confidential, being on Doctor Who was a long term goal of his, ever since the 60s, as was playing a part on Coronation Street.