During my genealogical journey I've come across many statements regarding decent from the Kings of England, Normandy and Lambeth ( Pearly King decent ).
Here we go :
1 ) 90% of Europe descended from Charlemagne
2) 50% of British descended from William I
3) 99.999 % of the English descended from Edward I
There are currently 61 million people living in Britain today. Let us assume 50 Million are native British ( those with ancestry back to the 9th, 10th & even 11th century ). At the time Charlemagne, William I and Edward I were taking part in that hobby 'procreation' , there were other people in the country involved in the same pastime. The population of England at the time of Domesday has been tentatively estimated at between 1¼ and 2 million.
So if we take Charlemagne, William I and Edward I out of the equation, then those 1-2 million would have only spawned either 50% of today's British or .0009% of today's English - according to the above statements.
I don't think the Math adds up, .......however.......I would much prefer to have descended from some mad Romana-Brit and been part of the ' Unique' minority then a common herbert from William the Bastard .
Descending from 'insert fav Royal connection here ' is only of any value if it can stand up to scrutiny ( i.e proven and backed up by good genealogical evidence ). Is it important ? Not really, but it's a journey that has a conclusion and a solid foundation in which to build the tree even further.
Royalty has been documented throughout the planet for most of its history, so its easier to trace your ancestry back to Charlemagne, William I and Edward I then it is to make a connection with Gundrid the mad axe wielding nutcase from Wessex in the year 540.
If Gundrid and his off-spring had kept records, then that would also fit into the above three rules ?