I was scanning the comments for someone to mention this. I, Claudius is a great show and for the many people who mainly know Stewart from Star Trek, his character is a very fun contrast from Picard.
"I, Claudius" (1976) had a number of excellent actors in it—many of them no longer with us. Most (if not all) of the 12 parts are on YouTube and/or archive.org.
(Highly recommended.)