Leo X
From Tardis Wiki, the free Doctor Who reference
Leo X was Pope in the early 16th century. His brother Guiliano de Medici confessed to Leo that he had angered the Ravelli family and believed Steven Taylor and Vicki Pallister to be part of an assassination plot. (AUDIO: The Ravelli Conspiracy)
Behind the scenes
Tom Baker played Leo X in the 1974 film Luther.