He has been rather informative for some 20 years on Time Team.
He wasn't the person that was informative, but the experts in their various fields. It was clear from the inane questions that Sir Tony asked them, that he was as dumb as a brick. Many times I was embarrassed for him that he could not wrap his mind around what was being discovered in a trench.
If you think I was referring to his acting roles, I have watched only a handfull of the Blackadder shows from the four different series runs and of course do not remember Tony Richardson's role, but for a momentary snapshot in my mind of a slapstick shtick where Rowan Atkinson hits him, I believe.