If DtG had said "Sir Pterry", Doug, would that have been any clearer?
Not really. I guessed that 'Sir Terry' referred to Terry Pratchet but 'Sir Pterry' makes no sense at all.
I looked up a Terry Pratchet reference to monarchy (which, unfortunately, I don't seem to ge able to make a link to). While I found it amusing, it was difficult to see how it fits into this thread other than a passing mention of Trump acting like a king.