 McDiarmid was only 37 at the time, and this convinced George Lucas and Richard Marquand that he could convincingly play a much older character in extreme cinematic close-up, which helped him land the role of Palpatine.After a minor part in the film "Dragonslayer", McDiarmid was cast by George Lucas in "Return of the Jedi" as Emperor Palpatine, the main villain.Sixteen years after appearing in "Return of the Jedi", he reprised the role as the character's younger incarnation of Senator (and later Chancellor) Palpatine and Sith Lord Darth Sidious in the prequel films