Question: Ian McDiarmid who stars in City of Vice was also famous for being which character in Star Wars?

Context articles: Lego Star Wars II: The Original Trilogy
Starkiller
City of Vice
Star Wars: Episode I – The Phantom Menace
Star Wars: Episode III – Revenge of the Sith
Ian McDiarmid
Star Wars: Episode II – Attack of the Clones
Star Wars: Thrawn
Star Wars: Darth Plagueis
Palpatine

Lego Star Wars II: The Original Trilogy is a Lego-themed action-adventure video game developed by Traveller's Tales and published by LucasArts and TT Games Publishing.
 It was released on 11 September 2006.
 Part of the "Lego Star Wars" series, it is based on the "Star Wars" science fiction media franchise and Lego Group's "Star Wars"-themed toy line.
 It follows the events of the "Star Wars" films "Star Wars", "The Empire Strikes Back" and "Return of the Jedi".
 The game allows players to assume the roles of over 50 Lego versions of characters from the film series; customized characters can also be created.
 Camera movement was improved from its predecessor—""; and the concept of "vehicle levels" was explored more thoroughly.
 The game was revealed at American International Toy Fair 2006.
 Promotions for the game were set up at chain stores across the United States.
Starkiller, born Galen Marek and also known as The Apprentice, is the Dark Jedi anti-hero protagonist of the "" project.
 In 2014, Lucasfilm rebranded him as part of the "Star Wars Legends" non-canonical story-line, and the character has not been re-introduced yet into the "Star Wars" canon.
 He is raised by Darth Vader and is made his secret apprentice under the name "Starkiller" due to being potent with using the Force for destructive purposes and described as less of an assassin and more of a "Force wrecking ball".
 The character's name is taken from Luke Skywalker's original name, "Annikin Starkiller".
 The character's likeness and voice are provided by Samuel Witwer.
 Despite "The Force Unleashed" being of non-canonical "Legends" status, Witwer still remains part of the "Star Wars" canon by voicing Darth Maul in the animated series "Star Wars: The Clone Wars" and "Star Wars Rebels".
City of Vice is a British historical crime drama television series set in Georgian London and was first screened on 14 January 2008 on Channel 4.
 It is produced by Touchpaper Television part of the RDF Media Group.
 The series mixes fiction with fact following the fortunes of the famous novelist Henry Fielding (Ian McDiarmid) and his brother John (Iain Glen).
 Henry and John Fielding were magistrates of Westminster and the men who created the modern police force in Britain through the Bow Street Runners.
 The series was written by Clive Bradley and Peter Harness, whose scripts were nominated for a Writers' Guild of Great Britain Award for Best Series, 2008.
 It was directed by Justin Hardy and Dan Reed.
 The historical consultant was Hallie Rubenhold.
Star Wars: Episode I – The Phantom Menace is a 1999 American epic space opera film written and directed by George Lucas, produced by Lucasfilm and distributed by 20th Century Fox.
 It is the first installment in the "Star Wars" prequel trilogy and stars Liam Neeson, Ewan McGregor, Natalie Portman, Jake Lloyd, Ian McDiarmid, Anthony Daniels, Kenny Baker, Ahmed Best, Pernilla August, Brian Blessed, Ray Park, and Frank Oz.
Star Wars: Episode III – Revenge of the Sith is a 2005 American epic space opera film written and directed by George Lucas.
 It is the sixth entry of the "Star Wars" film series and stars Ewan McGregor, Natalie Portman, Hayden Christensen, Ian McDiarmid, Samuel L. Jackson, Christopher Lee, Anthony Daniels, Kenny Baker, and Frank Oz.
 A sequel to "" (1999) and "" (2002), the film is the third and final installment of the "Star Wars" prequel trilogy.
Ian McDiarmid ( ; born 11 August 1944) is an Olivier and Tony award-winning Scottish character actor and director.
 He has appeared in 47 films since 1976.
 Internationally, he is most famous for his role as Palpatine in the "Star Wars" film series.
Star Wars: Episode II – Attack of the Clones is a 2002 American epic space opera film directed by George Lucas and written by Lucas and Jonathan Hales.
 It is the second installment of the "Star Wars" prequel trilogy, and stars Ewan McGregor, Natalie Portman, Hayden Christensen, Ian McDiarmid, Samuel L. Jackson, Christopher Lee, Temuera Morrison, Anthony Daniels, Kenny Baker and Frank Oz.
Star Wars: Thrawn (also known simply as Thrawn) is a "Star Wars" novel by Timothy Zahn, published on April 11, 2017 by Del Rey Books.
 It chronicles the origins of Grand Admiral Thrawn, a popular character originating from the "Star Wars Legends" line of works, which were declared non-canon to the franchise after Lucasfilm redefined "Star Wars" continuity in April 2014.
 The novel was announced in July 2016 alongside news that the character Thrawn would be reintroduced into the "Star Wars" franchise on the 3D CGI animated television series "Star Wars Rebels".
Star Wars: Darth Plagueis is a novel that is part of the "Star Wars" expanded universe.
 It was written by James Luceno, and released on January 10, 2012.
 The novel covers the later life and machinations of Sith lord Darth Plagueis, over a roughly fifty-year period pre-dating "Star Wars: The Phantom Menace".
 The novel details Plagueis' overthrow of his own master Darth Tenebrous, his work as head of a powerful banking consortium on the Muun homeworld, his discovery, recruitment and training of the teenaged Sheev Palpatine of Naboo, and the efforts of Plagueis to undermine the Galactic Republic and ensure the dominance of the Dark Side of the Force.
 The novel brings in scores of characters and locations already familiar in the "Star Wars" mythos, as well as introducing many others for the first time.
 Events depicted on-screen in "Star Wars Episode I: The Phantom Menace", are re-told in "Star Wars: Darth Plagueis", often from a perspective not shown in the 1999 motion picture.
Sheev Palpatine, also known as Darth Sidious and The Emperor, is a fictional character and one of the primary antagonists of the "Star Wars" franchise, mainly portrayed by Ian McDiarmid.
 In the original trilogy, he is depicted as the aged, pale-faced and cloaked Emperor of the Galactic Empire and the master of Darth Vader.
 In the prequel trilogy, he is portrayed as a charismatic Senator from Naboo who uses deception and political manipulation to rise to the position of Supreme Chancellor of the Galactic Republic, and then reorganizes the Republic into the Galactic Empire, with himself as Emperor.