Despite a résumé rich in classical stage roles and numerous accolades from the British critics, Scottish actor Ian McDiarmid was a pop cultural nonentity until he took an undemanding paying job as the despotic Emperor Palpatine in "Return of the Jedi" (1983), the second sequel to George Lucas' paradigm-smashing space opera "Star Wars" (1977). Obscured under heavy makeup for his time onscreen, McDiarmid could not have anticipated how much of a bite the role would take out of his professional life. Immortalized in Lucasfilm merchandising for 15 years as he returned to a purposeful career as an actor, director and theatrical impresario, McDiarmid was recalled to the franchise for "The Phantom Menace" (1999), a prequel to "Star Wars" that required the veteran actor to reinterpret the same character fifty years younger. He would play the vampiric Palpatine twice more, in "Attack of the Clones" (2002) and "Revenge of the Sith" (2005), but the stage would remain McDiarmid's true home. In 2008, the 61-year-old actor suffered a heart attack while performing at London's Gielgud Theater, but staved off an EMS crew until after he had taken his curtain call. Seen later as the star of the U.K. miniseries "City of Vice" (2008) and as controversial British Prime Minister Margaret Thatcher's doting husband in "Margaret" (2009), McDiarmid remained what he had long been to the theatregoers of London's West End: a consummate and highly valued character actor.