When First Cousins Marry

Many of my wider family lived in small isolated villages in the 18th and 19th centuries so it is not surprising that families frequently inter-married. My problem is that I find it impossible to present the information in a way that makes this clear. With any sort of ancestor chart, the inter-marriage is only apparent when I spot the same people turning up in two (or more!) places in the same chart. It would be nice to have a way of flagging this up automatically. At the moment I try to highlight these instances by colour-coding people who married a cousin, but I have to find the occurrence first.

In this example shown Robert Norman married his first cousin Martha Melhuish. Then his sister Jane married Martha’'s brother, so of course they were also first cousins. In the next generation it gets even more confusing because Robert and Martha’s son married John and Jane’s daughter. So this means that the happy couple were first cousins twice over, and second cousins twice over too! Moving on to the next generation, Mary Jane had 4 grandparents like we all do. But she only had 4 great-grandparents instead of 8. And she only had 6 great-great-grandparents instead of 16.

It would be nice to have a way of presenting these sorts of relationships clearly, either within Roots Magic or in some other way.

A useful article on the effects of 1st cousin marriage on a family tree is:

I hope this is helpful!

It is helpful. The chart with the swirly pink and blue lines is just the sort of thing I was looking for. In the next few days I’ll prepare a gedcom file and upload it, to see how it works out for my tree. Thanks.

And this is what the ancestors of Mary Jane Norman look like using the presentation suggested by GJH.

Worse than the royal family, and probably on a par with the Habsburgs! (Though not over so many generations.)

I created a Custom Fact Type: “Relationship to spouse”:

That’s a nifty idea too. I’ll try that.