Is that person in my family my fourth cousin, or my second cousin twice removed? I have to admit that as a genealogist and historian, I did not really understand how to figure out my relationship to others in my extended family. Sad, I know. But recently I decided to figure out this puzzle by doing a little research. Here is what I found out.
To figure out the relationship of you and a cousin, imagine a multi-sided pyramid with your common ancestor (example: Mary) at the top. The number of sides of the pyramid depends on the number of children your common ancestor had — in this case, two (Mary’s son and Mary’s daughter). Each step down the pyramid is a generation away from your common ancestor. Place yourself on the correct generation “step” down from Mary and do the same for your cousin in question (ex. Mary’s great, great grandson) by placing them on another side of the pyramid on their correct generation “step.”
Mary’s son Mary’s daughter
Mary’s granddaughter Mary’s grandson
Yourself Mary’s great grandson
Your son Mary’s great, great grandson
I learned that people directly across from each other are “numbered” cousins, by how many generations away they are from the common ancestor, minus one. For example, Mary’s granddaughter and Mary’s grandson are 1st cousins. They are two generations away from Mary, but are “first” cousins. ”Yourself” and Mary’s great grandson are 2nd cousins. Your son and Mary’s great, great grandson are third cousins.
But people in different generations (different levels) are “removed” cousins. So “yourself” and Mary’s great, great grandson are 2nd cousins, once removed. Make sense?
I recently discovered that I was related to many notable people through a common ancestor. This research information helped me figure out my relationship to them. I hope this will help serve as an illustration to our question.
Three of these notable people are Princess Di and Prince William, and Franklin D. Roosevelt. Our common ancestor is Elder John Strong who came through Plymouth colony in 1635 — about 15 years after the Pilgrims. He had 18 children by his wife Abigail Ford. Sixteen children lived to adulthood. I descend from their son, Jedediah Strong. Princess Di descends from their son, Thomas, and President Roosevelt descends from their son, Ebenezer.
Place Elder John Strong at the top of a pyramid and place each of his children on a different side of a 16-sided pyramid. As one descends down each step on each side, the relationships become clear. Princess Di and I are each 11 generations away from Elder John Strong, so we are 10th cousins. (And thus, I am tenth cousins, once removed, from her son, Prince William.) But Pres. Roosevelt is only 8 generations away from Elder John Strong, so he is my seventh cousin, three times removed. These numbers should equal the number of generations away (+1) from the common ancestor for the youngest person in the relationship.
Princess Di (10) = Melinda (10)
Roosevelt (7) +3 away equals 10 = Melinda (10)
Prince William (11) = Melinda (10)+1 away equals 11
I am so glad I finally figured this out! If you have any questions, let me know. And as far as a claim to the throne of England, I don’t think I have one. But I may go have a cup of tea!