One of the key techniques of DNA genealogy is to identify, classify and analyze shared matches between known cousins. When we find others who share DNA with two or more SAINSBURY cousins we can look at their family trees to see if they have a SAINSBURY ancestor.
Our goal in this phase of our project is to find shared matches whose SAINSBURY lines can be traced back prior to the 1720s. This would identify SAINSBURY families whose children were born around the time as our earliest known ancestor, Richard SAINSBURY. (Richard married Mary WILLIS in Portbury, Somerset in 1745. If we consider he may have been anywhere from 20 – 40 years old when he married, our ancestor would have been born between 1705 and 1725 — likely in Wiltshire, given the results from phase one of this project.)
When a shared match has a SAINSBURY ancestor it’s possible (even likely) that we all descend from a common ancestor on the SAINSBURY line. Additionally, the amount of DNA those matches share can provide a clue to when their shared ancestor was alive.
In genetic genealogy a match is considered to exist when a comparison of the DNA test results of two persons suggests there is a high probability of them sharing a common genetic ancestor within a relevant period of time.
International Society of Genetic Genealogy
This week we found a strong shared match between two half third cousins from our family who themselves share 137 centimorgans (cM) of DNA across four segments. According to the shared cM project tool this amount of shared DNA is well above average for individuals who share this relationship. It is, therefore, a great starting point to look for others who share DNA with those two cousins and who may therefore descend from our Somerset ancestor’s siblings or cousins. (See this post for a diagram that explains this concept.)
These third cousins share about 60 matches with more than 20 cM. Not all of them will be matches through the SAINSBURY line, but this week we found an early 18th-century SAINSBURY in the family tree of one of those matches. An Ancestry user in Australia who shares 26 cM of DNA with one of our cousins descends from a Martha SAINSBURY who lived in Corsley, Wiltshire in the 18th century.
Martha SAINSBURY was probably baptized in 1737 in Codford St Peter, Wiltshire. She married Gabriel SPAREY in Corsley, Wiltshire in 1769 — a gardener from nearby Boyton, Wiltshire.
One of their children was William SPAREY (b. 1772) whose daughter, Martha SPAREY (1791- ) married William MOODY (1784-1845) and had many children including Adam and Isaac. We have found DNA matches among our known SAINSBURY cousins to descendants of both of these men.
To return to Martha SAINSBURY (1737?-1811) who married Gabriel SPAREY in 1769. The results we’re finding suggest she could be a relatively close relation of our ancestor, Richard SAINSBURY (? – 1785).
More research and more DNA results and analysis are needed. But we’ve found some very suggestive DNA evidence by following the lead from that single shared match.
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.
The Mystery of Richard Sainsbury of north Somerset (? - 1785) 
2 thoughts on “Shared DNA Matches and the Sainsburys of Corsley and Codford St Mary”