I am going to start with a statement that too many historians prefer to ignore: England existed before 14 October 1066 and existed as a single kingdom for some of that time.
So why do our monarchs’ regnal numbers ignore this? Edward the Confessor died at the beginning of that very year. Edward the Martyr earned his nickname at Corfe Castle under a century earlier. Edward the Elder succeeded Alfred under two centuries before the twilight of the Anglo-Saxon monarchy. All reigned as part of the House of Wessex which outlasted the other heptarchs yet, when that name resurfaced under the crown in 1272, its bearer bore the number one (I).
Is it time to correct this? Should Prince George of Cambridge have sons with Saxon names and they succeed in due course, should they take adjusted regnal numbers eg Edmund III, Egbert IV? Should new editions of all general history books adjust the numbers of the Edwards to date?