Third Cousins

Third cousins? You mean I have more than just first cousins and second cousins? 

That’s right, folks! And I’m here to explain.

Let’s review, shall we? No, this isn’t a conspiracy meant to drive you insane although you may need to lie down with a cold compress and a hot cup of tea by the end of this.

What kind of cousins you are (first, second, third, etc.) depends on the most recent ancestor you share with your relative.

Your first cousin is someone with whom your closest (most recent) common ancestors are a set of grandparents. In other words, your first cousin is the child of your mother’s sibling or your father’s sibling. 

Your second cousin is someone with whom your closest common ancestors are a set of great-grandparents. You don’t share grandparents with your second cousin though. Click here for a refresher.

To demonstrate the meaning of third cousins, I (Mary Jane Culbert) have enlisted the assistance of my third cousin, Michael Gordon Dunsmore Culbert of North Bay, Ontario.

Michael Gordon Dunsmore "Mike" Culbert: my third cousin

Mike Culbert and I are third cousins. Our closest common ancestors are a set of great-great-grandparents named John Culbert and MaryWard. You might have heard of them?

 

John Culbert & Mary Ward are the great-great-grandparents of Mike Culbert & Mary Jane Culbert. These are the closest set of ancestors shared by Mike & Mary Jane. That makes Mike & Mary Jane 3rd cousins.

Mike and I don’t share grandparents. We don’t share great-grandparents either. However, we do share great-great-grandparents. 

My great-grandfather was Richard Culbert. Michael’s great-grandfather was Thomas Culbert. Our great-grandfathers Richard Culbert & Thomas Culbert were brothers, and their parents were John Culbert & Mary Ward. John Culbert & Mary Ward (our great-great-grandparents) are the closest set of ancestors from which we are both direct descendants.

Third cousins have a set of great-great-grandparents as their most recent common ancestors.

Got it? Good. Because we’re moving on now to third cousins, once removed. 

To demonstrate, I’ve enlisted the help of my third cousin, once removed ... Jillian (Culbert) Fleming of Powassan, Ontario.

Jill (Culbert) Fleming: my third cousin, once removed.

Jill (Culbert) Fleming is Mike Culbert’s daughter.

You already learned the meaning of “once removed” when you read about “first cousins, once removed.” Click here if you’ve forgotten. 

One generation of difference equals one remove. 

Jill is one generation removed (apart) from me and her father. Jill’s father Mike Culbert is my third cousin so Jill is my third cousin, once removed.

Mike Culbert (my 3rd cousin) with his daughter, Jill (my 3rd cousin, once removed)

Now that you're up to speed with the terms first cousin, second cousin, third cousin, and of course, “once removed,” you’ll understand when you read this article about how Queen Elizabeth II and Prince Philip are third cousins through Queen Victoria, and are also second cousins once removed through King Christian IX of Denmark.

Cousins. Fun for the whole family!