Sir Alec Guinness appeared in 60-some films, including those below. He won an Oscar for Best Actor for Bridge on the River Kwai at the 1958 Academy Awards.
He detested Star Wars, some sources say - thought he was far too classy an actor to be playing in such movies. He took the money though, and it was Star Wars which insured his wealth in later life. Maybe he didn't think he was too good for Star Wars. Maybe he was just tired of them.
Other UK actors winning Oscars for Best Actor include:
Rex Harrison (England) for My Fair Lady
Paul Scofield (England) for A Man for All Seasons
Ben Kingsley (England) for Ghandi
Daniel Day-Lewis (England) for My Left Foot
Jeremy Irons (England) Reversal of Fortune
Anthony Hopkins (Wales) Silence of the Lambs
Daniel Day-Lewis (England) There Will Be Blood
Colin Firth (England) The King's Speech
Many winners before 1960, and many from Commonweath nations. Also, many more were nominated but robbed. (Like Peter O'Toole and Albert Finney and several more.)