You will have no luck asking Europeans to ever start using arabic numerals for titles used by the royalty. Numbering centuries would be a much more approachable endeavour.
Bloody French.
Bloody French.
1. The President of France is also, ex-officio, Co-Prince of Andorra, so their president is a monarch, though he's not a monarch of France.
2. The Wallis and Futuna Islands, which are an overseas collectivity of France, is still divided into three kingdoms with recognised kings.