About 5 years ago I was the same flight with HRH The Prince of Wales from ZRH to LHR. We both were in J, he in 1A and me in 1F. 1C was taken by someone of his entourage and 1D by one of my colleagues (I’m not usually calling them entourage

). It was a regular A320, no royal kit ...
He was treated exactly the same as every J pax on board, but got escorted on board by State of Zurich police, as the last passenger to board the aircraft, and deplaned with Briitish police, as the first passenger.