The outgoing Chancellor Finis Valorum was played by Terence Stamp, most recently seen in "Yes Man (2008)" as inspirational guru Terrence Bundley who convinces Jim Carrey's character Carl Allen to stop being a "No Man" and to answer "YES" to everything. You might remember Terence Stamp as Kryptonian super-villain General Zod in Richard Donner's "Superman (1978)" which starred Christopher Reeve (man! it would be nice to have a 1/6 figure of this particular Superman, now that Hot Toys have done the Man of Steel played by Brandon Routh). Stamp went on to reprise his role as General Zod in the sequel "Superman II (1980)", directed by Richard Lester.
I like how George Lucas came up with the name for Valorum. He is "Finis" - ha! ha! Notice how the Senate Guard is blue and Royal Guard is red, just like the Blues & Royals and Life Guards of the Household Cavalry.