Thank you for pointing that out, Chequer, although I was thinking of that point but in an even wider perspective - by which I mean, the English seem to be historically the only ones that insist on their regnal numbering beginning with the Plantagenets. So, no one before the Conqueror - not even Edward the Confessor. Whereas, on the Continent as you point out there is an acknowledgement of the wider historic reality of previous dynasties - in Spain, before the Borbons. Or, in Norway and Denmark, before their present-day dynasties and houses.