Finding and validating triangulated matches is our current research focus as we try to identify the family of origin of our Somerset ancestor Richard Sainsbury (? – 1785). (See Triangulated Matches and the Vale of Pewsey.)

So we’re using genetic genealogy web sites to look for distant cousins whose family trees can be traced back to at least the early 1700s — the time period in which our earliest known Somerset ancestor would have been born.

On Ancestry, however, it is almost impossible to find shared matches among distant cousins. Why? Because on Ancestry the cut-off point for their “Shared Matches” tool is 20 centimorgans (cM). In other words, all those involved have to share at least 20 cM of DNA or they won’t appear when you click “Shared Matches” in Ancestry.

This effectively means the distant cousins we’re looking for — who almost always share less than 20 cM with each other because they are so distantly related — will almost never appear when you click Ancestry’s “Shared Matches” tool:

But earlier this year we caught a break.

Distant match reveals more

On Ancestry, one of our Somerset Sainsbury cousins shares between 7 and 10 cM of DNA with two siblings (MR and JR) whose ancestors include two couples who are ancestors of Richard Sainsbury baptised in Urchfont in 1708:

Those couples are:

• John NUTLAND (1603 – aft.1635) of West Lavington, Wiltshire who married Joane HURL (c.1610 – ?) of West Lavington, Wiltshire
• John EDWARDS (c. 1570-1610) of Urchfont, Wiltshire who m. Ann NOYES or SHERGOLD (c. 1575-1636) of Urchfont, Wiltshire

Now, there’s nothing to prove that the DNA shared by MR, JR and our Somerset Sainsbury cousin was inherited from either of these Urchfont couples.

However, it seems highly likely that one of these four people was the source of the shared DNA. And if so, it would almost certainly prove that the Richard Sainsbury baptised in Urchfont in 1708 is the same person who married in Portbury, Somerset in 1745 and was buried in Nailsea, Somerset in 1785.

In other words, it would prove that the Sainsburys of North Somerset are, in fact, a branch of the Sainsbury family of Urchfont which can be traced back to the early 1500s.

Shared matches on Ancestry? Yes!

One way to examine the likelihood that two distant matches on Ancestry inherited their shared DNA from a given couple is to look for other shared matches whose family trees can validate the source of the DNA.

For example, if our Somerset Sainsbury cousin and the two siblings with whom he shares this DNA all match a third person, that person’s tree would validate the match if it includes the same common ancestors.

In this case, Ancestry’s “Shared Matches” tool actually produced a result:

This shared match (LP) only had 5 people in her online family tree. But with a bit of work it became clear that she is a third cousin (once removed) of MR and JR.

Likewise, her family tree can also be traced back to John and Ann EDWARDS of Urchfont and John and Joan NUTLAND of West Lavington, Wiltshire.

So now we have:

• A Somerset Sainsbury cousin who shares a segment of DNA with two siblings who descend from the Urchfont Richard Sainsbury’s great-grandparents (John and Joan NUTLAND of West Lavington) and his 2nd great-grandparents (John and Ann EDWARDS of Urchfont).
• The same Somerset Sainsbury cousin shares a segment of DNA with a third cousin of those siblings (LP) who also descends from John and Joan NUTLAND of West Lavington and John and Ann EDWARDS Urchfont.

The trees

For those with an interest, here are the family trees showing these relationships — and the evidence they may provide of our origins in the Sainsbury family of Urchfont:

Next steps?

We could go much further with this investigation if any of these distant matches (MR, JR and/or LP) were to upload their DNA tests to MyHeritage.

On MyHeritage, it would be possible to:

• verify that all involved share the same segment of DNA, which would strongly suggest their descent from a common ancestor,
• locate others who share the same segment of DNA,
• see if their family trees indicate which (if either) of these Wiltshire couples was the source of the shared DNA,
• validate the theory that their shared ancestry is evidence that the Richard Sainsbury baptised in Urchfont in 1708 is the ancestor of the Sainsbury family of north Somerset (and beyond).

Other triangulated matches are under investigation in this project. But this is one of the best because the family lines are well documented, and they leads to not one but two couples — either of which could prove the Urchfont origins of the Sainsbury family of north Somerset.

Interested in genetic genealogy?

Check out these resources that describe the science of triangulated matches:

Triangulating autosomal DNA National Genealogical Society NGS Magazine 42 (October-December 2016): 39-42.

Triangulation. ISOGG wiki. (Last updated September 19, 2019; accessed February 18, 2020).

Triangulation is the icing not the cake by Shelley Crawford, Twigs of Yore, 3 March 2018.

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.

• England, Wiltshire, Urchfont