Analysis by Keith Rankin – Chart of the Month – Descended from Royalty?
While reading a news-site recently, I caught a link to the following from ancestry.com: Do You Come From Royalty? While the article itself doesn’t actually mention “royalty”, it’s true that many people wonder if they are descended from someone famous or infamous (or both); say King Henry the Eighth, or King Edward the First (who reigned in 1300).
To determine whether you are descended from royalty, you don’t have to subscribe to Ancestry. Just do the maths. King Henry reigned 17 generations ago, while King Edward goes back 25 generations. It turns out that, 17 generations back each of us has 131,072 ancestors; 25 generations back we have 33,554,432 ancestors. (Of course most of these will not be unique ancestors, especially given that Britain had a reproductively active population in the year 1300 of about one million people, and that most New Zealanders have substantial British ancestry.)
My chart shows that, while the chance of an ethnically British person being descended from any given reproductively active British person in King Henry’s time is about four percent, the chance of being descended from any given such person in King Edward’s time is 100 percent (actually, a probability of one, rounded to 15 decimal places). Most of us will have King Edward – and most of his subjects – multiple times in our family trees.