My first recollection of O’Toole as a kid was in the Masada mini-series on TV. Great show (or at least I thought so as probably a 12 year old or so). He was totally believable in the part, which is a a sign of a good actor.
I love this/his line from Masada toward at the end of the movie. I can hear him saying it...
Cornelius Flavius Silva: A victory? What have we won? We’ve won a rock in the middle of a wasteland, on the shores of a poisoned sea.