Simplify the following text for a Grade 7 native English-speaking person.
Original: Worldwide , he is most famous for his role as Emperor Palpatine in the Star Wars live action film series ( both the original and prequel trilogies ) .
Simplified: Worldwide , he is most famous for his role as Emperor Palpatine in the Star Wars live action film series . He was in both the original and prequel trilogies .