Niccolo Machiavelli
From Tardis Wiki, the free Doctor Who reference
Niccolo Machiavelli was a writer and politician. The First Doctor, Steven Taylor and Vicki Pallister landed inside his house in Florence, Italy in 1514. (AUDIO: The Ravelli Conspiracy)
Machiavelli acted as an adviser to Parallaxia div Procyon during the City of the Saved Civil War. (PROSE: Interlude from a Civil War)
Behind the scenes
Machiavelli has been played by Sam Dastor and Julian Bleach in unrelated television series about the Borgias.