Charlemagne had so many children also, I saw somewhere that if you are living in Europe or have ancestry from Europe, the likelihood is very high that you are related to Charlemagne somehow. Similarly for Asia and Genghis Khan. Its all one tree, but some folks have an outsize influence on that, and those people tend to be the wealthy and especially those with large families (because they are more likely to be in the records, they live longer, they have a better chance of more children living to have their own families, etc.)