It's really nice seeing those pubs the are really connected to a tumultuous history.
The oldest pub I've been not too far from is "The Old Ferry Boat Inn". The structure isn't that old, dating to the 17th Century. It is claimed to date to 560 AD, but if you believe that, I have a bridge (very old) I'd like to sell you.
People getting continuously drunk since 560 AD somewhere seems a little more believable than the oldest pub in a state managing to be a speak easy during prohibition.