Month: May 2020

Looking for a long shot: Triangulated matches to distant Sainsbury cousins

The previous blog post detailed the results of our year-long search for distant cousins who relate to the Sainsburys of north Somerset through our earliest known ancestor, Richard Sainsbury (1708?-1785).

Although we found close to 100 genetic matches that strongly suggest our Sainsbury family and place of origin is in Urchfont, Wiltshire, we did not find a single triangulated match.

The power of three

A triangulated match would include at least two Somerset Sainsbury cousins and at least one person who descends from an ancestor of the Richard Sainsbury who was born in Urchfont in 1708:

In this diagram, two Somerset Sainsbury cousins (on the right) and a documented descendant from the extended family of Richard Sainsbury of Urchfont (on the left) share the same segment of DNA. This triangulation suggests the segment of DNA was inherited from a common ancestor.

Alternately, the triangulated match we’re looking for could include at least two cousins (of some degree) descended from a sibling or ancestor or Richard Sainsbury of Urchfont, and at least one Somerset Sainsbury cousin.

In any case, the important thing is for those three (or more) people to share an identical segment of DNA. If they do, it’s reasonable to assume they all inherited that DNA segment from a single common ancestor.

Because we’d have a paper trail showing how the “unknown” match descends from the family of Richard Sainsbury of Urchfont (b. 1708), we could reasonably assume our own ancestor, Richard Sainsbury (d. 1785), is the same person. Otherwise, how would the Somerset Sainsbury cousin(s) have inherited the same segment of DNA?

It’s impossible to determine this type of match on Ancestry, which is why GEDmatch and MyHeritage are so important for this work. Those sites have tools called chromosome browsers that show exactly which segments of DNA any two or more people share.

GEDmatch and MyHeritage

The focus of this project has now turned to the hunt for this type of triangulated match.

We have many candidates, but most will need to upload their Ancestry DNA files to either GEDmatch or MyHeritage–depending which platform already hosts the DNA tests of those they match.

The “high priority” leads for this investigation are the matches we found between Somerset Sainsbury cousins and descendants of two sisters and a brother of Richard Sainsbury (b. 1708) of Urchfont:

However, we have identified many other “In Common With” and “Singleton” matches that could, with additional research, become triangulated matches that help us solve The Mystery of Richard Sainsbury.

Download the detailed report of genetic matches here:

A big thank you!

A big THANK YOU to all the Somerset Sainsbury cousins and genetic matches who are helping with this research by uploading or sharing their DNA files for further research. We’ll never find the answer to this mystery without your help.

We’ve come a long way since this project began in early 2019.

Now let’s find those triangulated matches and destroy this Sainsbury brick wall.

Ruins, Derelict, Bricks, Crumbling, Old, Disintegration

Disclaimer: As with any research project, when new evidence comes to light, former theories may change. This blog post includes theories and conclusions developed from the best available evidence at the time this post was written. It may be corroborated or refuted by later research. This post must therefore be considered in the context of all information presented in earlier and later posts.