We need your help to solve a centuries-old mystery!
If you are a descendant of John Coat and his wife Elizabeth Richards — or one of John’s siblings — and you’ve taken a DNA test (or would be willing to), you could be the key to confirming whether his parents were actually Marmaduke COAT and Amy HEWLETT or someone completely different.
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| John Coat 1826-1907 |
Who was John Coat?
Born in Huntspill, Somerset, England in 1826
Arrived in South Australia in 1848 aboard the Princess Royale
Married Elizabeth Richards in 1851 in Adelaide, South Australia
Had 12 children (sadly, three died in infancy)
Died in 1907 in South Australia, aged 81
Despite extensive DNA analysis since 2010, we still have limited data to confirm John’s parentage. Y-DNA analysis however has revealed something fascinating — our COAT patrilineal line may trace all the way back to Roman times! ⚔️
Our ancestors are believed to have been Sarmatian cavalrymen, sent to Britain around 175 AD by Emperor Marcus Aurelius. But how John fits into that ancient story is the big question — and that’s where you come in! Help us determine if our patrilineal line name is Coat, Bennett or Locke?
How can you help?
Right now, no known descendants of John’s siblings carry the Y-DNA signature we’re studying. We have two testers from John, one via his son Charles and one via son Thomas, these tests confirm their relationships.
To move forward, we need:
Male descendants (for Y-DNA testing) - ideally male descendants of brothers of John's father, Marmaduke Coat b1791. He had two brothers James 1786 (m Mary Dunstone) and John 1789 (m Elizabeth Watch) but research suggests they have no male descendants still carrying the Y-DNA signature.
Any descendants (for autosomal DNA testing, eg AncestryDNA or FTDNA etc). In the absence of any suitable Y-DNA testers, the autosomal DNA of any descendant of John or his father Marmaduke, male or female, may hold the vital clue we are looking for.
Already tested? Or willing to? Great! Here’s what you can do.
Autosomal DNA Testers (Descendants of Marmaduke or John)
If you have already tested at AncestryDNA it would be great if you could share your AncestryDNA match list - so we can work together to find more common matches - Here's how to collaborate.
If you have already tested your DNA at AncestryDNA or any other site, please upload your kit to one, or preferably all, of the following companies. We need to be able to compare family members with each other:
🧬 FamilyTreeDNA (join the John Coat, Princess Royale 1848 Project - see link below)
🧬 GEDmatch (connect with testers across different testing companies)
🧬 MyHeritage (free upload!)
Uploading your results to multiple companies can widen your results. Here's how to transfer your DNA.
👉 Join the FamilyTree DNA John Coat, Princess Royale 1848 Project
👉 Join our AncestryDNA Family Group
Y-DNA Testers (Male descendants only)
If you are a male descendant of Marmaduke or John through your direct paternal line:
Test your Y-DNA with FamilyTreeDNA (minimum 37 markers; ideally Big-Y)
Join the John Coat, Princess Royale 1848, COAT surname and Bristol Channel projects
Upload results to mitoYDNA to maximise matching potential
(Remember: Y-DNA traces the direct paternal line — critical for this research!)
mt-DNA Testers (Female descendants of Amy (aka Emma) Hewlett)
If you’re descended from Amy Hewlett through your direct maternal line, you may be the tester we need! At present we don't know of many people who have inherited Amy's mtDNA but if your Hewlett ancestors aren't on Wikitree yet - you may be one of them! You would need to be descended via one of Amy's 2 daughters or her sister Mary Hewlett b1787. Amy's daughter Amy Ann Cote married John Norman and had 5 girls, but Caroline Cote married twice but had no children (m Henry Raymond and Peter Unsworth).
Test your mtDNA at FamilyTreeDNA
Join mtDNA haplogroup projects and our John Coat, Princess Royale 1848 project
Upload your results to mitoYDNA (accepts both Y and mtDNA)
mtDNA is an important tool for tracing maternal ancestry!
X-DNA - Chromosome 23: Autosomal DNA Testers (selected male and female descendants of Amy aka Emma, Hewlett)
If you’re descended from Amy Hewlett through the X-DNA line, you may share autosomal dna which may help! There are many more people who have inherited Amy's X-DNA but these can be harder to identify - ideally your results need to be on GEDmatch to be able to compare results.
🧬 GEDmatch - Upload your results so we can compare results with other family members, specifically on the X-chromosome.
X DNA is tested by all autosomal testing companies, but only reported at GEDmatch, FTDNA and 23andMe. GEDmatch is the best site for advanced DNA analysis tools!
Need more info?
🎄 Wikitree - Marmaduke and Amy and their known descendants
🧬 Genemonkey Blog – “John Coat: The South Australian Immigrant” (Published July 2020)
🎥 YouTube – “The Y-DNA of the COAT Family of South Australia” (Published Sept 2023)
Need help?
If you have any questions about testing, uploading results, or joining the projects, feel free to contact me via:
📧 Contact form on this blog
📬 Private Message at WikiTree
📬 Private Message at Ancestry, username genemonkey.
Together, we can solve this mystery — and bring the COAT family story to life!
Thank you for being part of this adventure!
Veronica Williams, May 2025
2nd great grand daugher of John and Elizabeth Coat.
