Kings and Farmers in Your Family Tree

People in Biblical times kept an oral history (and later a written history) that included their ancestors. The New Testament had two separate and very detailed genealogies of Jesus. No doubt, the Proverbs 31 family was aware of their ancestry. What more exciting project for you to do with your children while quarantined than to trace your family history!

I’ve written about this before as it is a hobby of mine, and I recently came across an article that intrigued me. In 2012, a 12 year old California girl traced the genealogy of all the residents and discovered that 42 of them descend from King John Lackland, known for signing the Magna Carta in 1215 (I myself have 2 lines descending from him.)

This is nothing special. I can almost guarantee you also have royal blood, and it all comes down to little math: you have 2 parents, 4 grandparents, 8 great-grandparents, 16 great-great grandparents, 32 great-great-great grandparents, and so on… As you go back generation by generation, the number of individual ancestors  grows exponentially and will soon exceed the total population of the world at that time.  30 generations (back to the Middle Ages) would give you theoretically over 1 billion ancestors. 40 generations (to the Dark Ages) gives you over a trillion ancestors, at a time when the planet’s population was around 200 million.

More math: if you divide your theoretical 1 trillion ancestors by the actual population of 200 million, and the average ancestor would appear on your family tree 5,000 times.  Then it gets more complicated. For this to happen, many died in infancy and childhood, so all of the 200 million alive in the Dark Ages did not produce children – many didn’t and so wouldn’t appear on anybody’s family tree, meaning that other ancestors would actually appear many more than 5,000 times.

Kenneth Wachter first illustrated this in his 1980 book “Ancestors at the Norman Conquest”. He calculated that in 1977 an average person born in 1947 would have had 32,768 theoretical ancestors 15 generations ago (at 30 years between generations), around 1527 AD; of these, 96% would have been ‘real’ and 4% duplicates.  Going back 20 generations to 1377 AD and he would have over 1 million theoretical ancestors, 40% of which would be duplicates.  25 generations ago, around 1227 AD – not long after the reign of King John – he would have over 32 million theoretical ancestors, 94% of which would be duplicates and only 6% ‘real’, i.e. 2 million, or 80% of the estimated English population of 2.5 million at that time.

The earliest it happened in my family tree was in the 1700s, when I discovered that I descend from both a son and a daughter of Edward Hicks. A more extreme example is that of Alfonso XIII of Spain (1886-1931), who only had 4 great-grandparents instead of the usual 8 because of royal inbreeding.

Your family tree is diamond-shaped rather than an inverted pyramid.  As you go further back the number of ancestors in each generation increases steadily up to a point, then slows, stops, then reduces.  And as there are fewer people to put on the branches of the 7 billion family trees of people living today, it is a mathematical certainty that, at some point, there will be an ancestor who appears at least once on everybody’s tree – the ‘most recent common ancestor’ of all humans currently alive.

This also explains why we are all descended from Charlemagne, and I have been able to trace back 10 lines so far. Here’s where the royalty comes in: Those who were more likely to survive and have children of their own were those from wealthy families. With these families arranging marriages for financial and political gain, we have sons and daughters of royalty marrying into noble families.

However, in the period between the 15th and 16th centuries, we see a large migration from England and other parts of Europe to North America. Money wasn’t as important as the ability to grow food. Now money and titles were less important than the ability to grow food and those with the largest farms became the new leaders of these colonies.

Here is the link to my post on Charlemagne.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s