Royalty in general, but especially the European one, is just an anachronism. Kings of Europe didn’t have nationality, they were supra-nationals. For centuries, they got married “in family”, becoming all relatives.
The former king, Michael of Hohenzollern-Sigmaringen is not German, but he is part of Hohenzollern dynasty. The Tsar Nicholas the Second was cousin with his wife. Tsar’s parents were cousins and his grandparents were also cousins. Can you realize this crap?! The Tsar suffered of hemophilia because of that. They were all degenerates.