Proof of descent from Blennerhassett Baronets family
Theory of our descent from Blennerhassett
explains the background
to the search for our family's Blennerhassett ancestry.
Evidence on that page shows what lines looked promising.
I began with a
Theory of descent from Letitia Blennerhassett of Tarbert.
The documents looked good. So I turned to DNA.
I gathered many DNA samples that should have lit up with matches, and they did not.
I decided I had proved the theory false.
It was clear
that if I ever found the right Blennerhassett branch, the DNA hits would be strong and obvious.
So, assuming we were connected to some Blennerhassetts, I looked for a "Plan B" branch of Blennerhassett to DNA test.
This was the very first DNA comparison I did
once I switched over to the Baronets theory.
And it immediately gave a massive hit.
The Baronets theory is true.
Proof that we descend from the Blennerhassett Baronets.
On 26 May 2020, this
15
centimorgans (cM)
hit was discovered on
my very first sample with the Blennerhassett Baronets.
We did just 11 one-to-one DNA comparisons and immediately got a rock-solid 15 cM.
The match is between these two people:
After the breakthrough with Chute,
other DNA matches came spilling out.
Multiple matches, and different sides of the family.
Though smaller than the Chute match, until Oct 2020, when we got one bigger than the Chute match.
On 18 Oct 2020, we got the following huge 21 cM
match with the Baronets family.
We have multiple DNA matches of our family now with descendants of the 2nd Baronet.
There is no doubt now. The Baronets theory is true.
We have a match between:
and three people in my family:
DNA match of Sir Adrian Blennerhassett, 7th Baronet, with Nuala Duggan,
as seen on Gedmatch.
See
full details of all the matches.
Our family has DNA links to the Blennerhassett Baronets family
(the Blennerhassett/Yielding family)
which clearly go through
Blennerhassett Cashel,
he being the common ancestor of people in our family with these DNA matches.
DNA links through Blennerhassett Cashel
to Blennerhassett/Yielding people must
in fact be links
through his father George Cashel,
and not through his mother or either of his wives.
Let us explain:
- Any link to Blennerhassett/Yielding probably goes through Co.Kerry.
- Blennerhassett Cashel's father
George Blennerhassett Cashel
is of Co.Kerry,
and has a well-developed paper theory of connection to Blennerhassett.
- Blennerhassett Cashel's mother is
Kickham of Co.Tipperary
and has nothing to do with either Co.Kerry or Blennerhassett.
- Blennerhassett Cashel's 1st wife is
Lyons of Co.Cork
and has nothing to do with either Co.Kerry or Blennerhassett.
- Blennerhassett Cashel's 2nd wife is
McSwiney of Limerick and Co.Cork
and has nothing to do with either Co.Kerry or Blennerhassett.
Realistically, any link to Blennerhassett/Yielding
through Blennerhassett Cashel and either wife
is a link
through George Cashel
and not through any other line.
Any link to Blennerhassett/Yielding
through George Cashel and his wife
is a link
through George Cashel
and not through any other line.
Our family has
more DNA matches with the Blennerhassett Baronets family.
Our family has matches with
William Yielding (born 1750-51),
brother
of
Millicent Agnes Yielding
(wife of 1st Baronet).
Our family has matches with
Belinda Yielding (bapt 1758),
sister
of
Millicent Agnes Yielding
(wife of 1st Baronet).
What Yielding matches mean is complex since the 1st Baronet's mother was also a Yielding.
We will discuss this below.
We have moved the details of all DNA matches, and all analysis of DNA ("triangulation"),
to a separate page:
Among these, we got the biggest match of all,
a 24 cM match with the Belinda Yielding line.
The conclusion is as follows:
I call it as proved that Arthur Blennerhassett of Blennerville
is related to our family through George Cashel and not through any other line.
I call it as proved that Sir Robert Blennerhassett, 2nd Baronet,
is related to our family through George Cashel and not through any other line.
I call it as proved that William Yielding
is related to our family through George Cashel and not through any other line.
I call it as proved that Belinda Yielding
is related to our family through George Cashel and not through any other line.
The biggest match of all is a 24 cM match between
Vincent Butler
(descendant of Belinda Yielding)
and
Rosaleen Riordan
(descendant of George Cashel).
See
full details of all the matches.
Let us summarise all DNA matches between my family and the Blennerhassett Baronets family.
I set the bar at 9 cM for a "significant" match.
In the list of all DNA hits
you will see I have even more matches.
There are marked as matches by genealogy sites, but are below 9 cM.
In the following summary I just look at strong matches, of 9 cM and above.
Cousin numbers
Let us show what
cousins these people are meant to be.
Let us assume that
George Cashel's parent (father or mother) is
a child (son or daughter) of
Sir Rowland Blennerhassett, 1st Baronet, and Millicent Agnes Yielding.
Then we use cousin numbering as follows:
5.0 - 5th cousin (direct, no times removed).
5.1 - 5th cousin, once removed.
5.2 - 5th cousin, 2 times removed.
...
6.0 - 6th cousin (direct, no times removed).
...
It is just about possible that George Cashel is great-grandson of the 1st Baronet,
if we have 20 year generations.
So we would need to shift the cousin numbers.
But we will stay with the assumption above for now.
The summary
We have the following matches with
the descendants of Sir Rowland Blennerhassett, 1st Baronet, and
Millicent Agnes Yielding.
We have the following matches with
the descendants of William Yielding,
brother of Millicent Agnes Yielding.
These people also descend from siblings of the 1st Baronet.
We have the following matches with the
descendants of Belinda Yielding,
sister of Millicent Agnes Yielding.
For the cousin numbers,
we assume Thomas and Tobias
are two generations below Belinda Yielding.
Remember there are more matches, below 9 cM.
Could all of these happen by chance?
Recall
we chose the family first, based on fragments of evidence in the documents,
and then, having picked the family in advance, we got these hits.
It is quite a list to get by chance.
-
With the
Letitia theory,
we did hundreds of one-to-one DNA comparisons
and we got just four matches above 9.0 cM, all below 10.7 cM.
We actually think all four may just be by chance
and not through the Blennerhassett line.
- Elsewhere in our testing, we did once see
12.4 cM by chance.
- But could we see a 20 cM by chance?
Could all of the above happen by chance?
-
We chose the family first, based on documents, and then got these hits.
It is quite a list to get by chance.
Let us summarise all the DNA matches on a tree or trees.
Our family is a DNA match to multiple members of the Blennerhassett Baronets family,
which itself is tightly inter-connected with the Yielding family.
These trees shows the complexity of the Blennerhassett-Yielding family.
The Blennerhassett-Yielding family is so complex that we cannot fit all our matched lines on one tree.
1st Baronet family matches
There are matches with descendants of two of the sons of the 1st Baronet.
The tree is complex because of the two 1st cousin marriages.
Richard Yielding
|
+------+-----------+
| |
Robert Blennerhassett = Frances Richard
| |
+-------------------------+-------+ |
| | |
Arthur 1st Baronet = Millicent Agnes
| |
| +----------------------------------+-----------------+
| | |
Rosanna = 2nd Baronet Arthur
| |
| |
DNA MATCH DNA MATCH
21 cM 15 cM
Matches outside 1st Baronet family
This chart is actually more complex than shown.
There are matches with two descendants of William Yielding.
One is
also a descendant of Sarah Blennerhassett.
The other is
also a descendant of
both Millicent and Sarah Blennerhassett.
The Belinda Yielding matches are straightforward.
Richard Yielding
|
+------+-------------------+
| |
Robert Blennerhassett = Frances Richard
| |
+-------------+---------+-----+ +---------+--------+------------+
| | | | | |
Millicent Sarah 1st Baronet = Millicent Agnes William Belinda
| | | |
| | | |
DNA MATCH DNA MATCH DNA MATCH DNA MATCH
17 cM 17 cM 17 cM 24 cM
We connect closely to this Blennerhassett-Yielding family. But where?
- Note first that every match descends from Yielding.
So in theory we could descend from Yielding and not from Blennerhassett.
The best match in fact descends from Yielding and not Blennerhassett.
-
I think we must descend from Blennerhassett though,
since my family used the name "Blennerhassett".
We will consider this theory again below.
- If we do descend from Blennerhassett,
then we must descend from
Robert Blennerhassett and Frances Yielding.
- Could we descend from one of Robert Blennerhassett's daughters?
Possible, but then the Blennerhassett name would be very far back.
Why would George Cashel
start using the name "Blennerhassett" in the 1840s?
- The most likely theory is we descend from Robert Blennerhassett's son,
i.e. from the 1st Baronet
or his brother Arthur.
- To get the high DNA match with the Belinda Yielding line,
I think it more likely that we descend from the 1st Baronet and his wife Millicent Agnes Yielding.
- There are multiple ways we could connect and still get these DNA numbers.
It is too far back for DNA to tell us for sure.
We connect closely to this Blennerhassett-Yielding family.
But ultimately we cannot know exactly where and how we connect to them
until we find documentary proof.
Let us try to summarise all possible theories:
- No Blennerhassett ancestry. They are not even relatives.
- No Blennerhassett ancestry. But they are relatives. Descent from Yielding.
- Blennerhassett ancestry through Cashell line.
- Blennerhassett Baronet ancestry.
- Other Blennerhassett ancestry.
Theory: No Blennerhassett ancestry. They are not even relatives.
- Summary of theory:
- George Cashel has no Blennerhassett ancestry.
- He used the name "Blennerhassett" as a tribute to Arthur Blennerhassett, who helped him join the police.
- There is in fact a Blennerhassett tribute in the
Mahany family.
- Against this theory:
- Family story of descent from Blennerhassett: Must be false.
- "Letitia Blennerhassett" story: Must be false. But why remember such an unusual name?
-
The big problem with the theory is: How do you explain the DNA matches?
Theory makes no sense.
- Summary of theory:
- George Cashel descends from Yielding.
He has no Blennerhassett ancestry.
e.g. He descends from
Millicent Agnes Yielding's sibling.
- This explains the Yielding DNA matches.
- This can also explain the Blennerhassett DNA matches since those people descend from Yielding too.
- "A. Blennerhasset, J.P." is still a close blood relation.
- George Cashel has no Blennerhassett ancestry.
But he is cousin of the Blennerhassett Baronets.
He adopted the name of his cousins as a tribute.
Maybe because his cousin Arthur Blennerhassett helped him join the police.
Note that the
Mahany tribute
is to in-laws/cousins.
- Against this theory:
- Family story of descent from Blennerhassett: Must be false.
- A bigger problem:
- "Letitia Blennerhassett" story is pretty hard to explain.
Letitia Hurly
is now the wife of a cousin, rather than a close relation.
- The big problem: Why use the name Blennerhassett?
- Why did George Cashel call his son "Blennerhassett" in 1848?
He certainly got excited about the Blennerhassett name if it was only some in-laws and cousins,
and not his parent or grandparent.
- If it was a tribute to the 1st Baronet,
or to his cousin Arthur who helped him get the police job,
why not use "Rowland" or "Arthur"?
The use of just "Blennerhassett" suggests family descent, not a tribute.
Also, why wait 20 years?
Why the tribute with George's youngest son not an elder son?
- Note that the
Mahany tribute
used "Rowland Blennerhassett Mahany",
not just "Blennerhassett".
- I think our family usage of just the name "Blennerhassett" kills this theory.
- Butler natural children:
- Letitia Yielding:
- There is in the Yielding family a
Letitia Yielding
of Tralee, born 1777 (age 29 in 1806), died 1844.
Could she be George Cashel's mother?
- She is the only Letitia Yielding I can find, in any time period,
and some of the details fit:
It seems that her father had a natural son in 1772,
and that son (Letitia's brother) had natural children in 1793 and 1803,
and her father died 1804.
Maybe Letitia then ran away with Mr. Cashel in 1806?
-
Her father is 1st cousin of both
Sir Rowland Blennerhassett, 1st Baronet, and his wife Millicent Agnes Yielding.
- But she still seems a bit far away to be getting those DNA matches.
A 2nd cousin of the 1st Baronet's sons.
Even if a double 2nd cousin.
-
Also, if she is Yielding and ran away with Cashel, then why use the name "Blennerhassett"?
She is 2nd cousin of Blennerhassetts
but that is too weak a connection to use the name.
DNA says we should keep this theory
alive.
But I think our family usage of the name "Blennerhassett" kills this theory.
Theory: Blennerhassett ancestry through Cashell line.
- Summary of theory:
- For this theory:
- We already have a Cashel family linked to Blennerhassett. No need to find a second link.
- Family story of descent from Blennerhassett: True.
- Against this theory:
- Runaway story: Must be false. The 1720s marriage was not a runaway.
- Churchtown story: Must be false.
- "Letitia Blennerhassett" story: Must be false. But why remember such an unusual name?
- "A. Blennerhasset, J.P." is then a very distant relation.
- Bigger problems:
-
"Blennerhassett" is not a middle name or first name in this Cashell family
in the 18th century.
Why would "Blennerhassett" suddenly emerge
as a middle name
and first name in our Cashel family in the 19th century?
(George Cashel was born 1807.
He called his son
Blennerhassett Cashel in 1848.)
- The strong DNA matches with the 1st Baronet family are very hard to explain.
The common ancestor would be too early.
- The big one: This theory cannot explain the Yielding DNA matches at all.
Theory makes no sense.
Theory: Blennerhassett Baronet ancestry.
- Summary of theory:
-
George Cashel does have Blennerhassett ancestry.
He descends from Robert Blennerhassett and Frances Yielding.
-
Probably through their son, either the 1st Baronet or Arthur.
Descent through their daughter seems less likely.
(Why did George Cashel start using the name "Blennerhassett"?
It would be too far back.)
-
To get the high DNA match with the Belinda Yielding line,
I think it most likely that we descend from the 1st Baronet and Millicent Agnes Yielding,
rather than from Arthur.
- For this theory:
- It explains the use of the Blennerhassett name.
- It explains the DNA.
- Family story of descent from Blennerhassett: True.
- Churchtown story: True.
- "Letitia Blennerhassett" story:
Could be explained by Letitia Hurly.
She is a close relation.
- There are natural children in this family:
- Against this theory:
- It is actually the most dramatic theory of Blennerhassett descent you could imagine.
A close relation of the only Blennerhassett that got a title.
I can see how it seems far fetched.
This is in fact why I rejected it when I first heard it in the
Gortatlea letter.
But the fact is, this is where the evidence leads.
Especially the DNA evidence.
I abandoned the Baronets theory for over a decade.
But the evidence has brought me back here.
-
Most likely an unnoticed event:
- A runaway marriage of a daughter from this family
would be the most dramatic version, and a huge scandal in Kerry.
And there is no evidence for it.
Not even a candidate for the daughter. We would have to find a new person.
- I suspect it was more ordinary. The oldest story on earth.
A Blennerhassett man had a natural child, and then moved on.
Back to his wife, most likely.
A natural child who is either
George Cashel
or ancestor of George Cashel.
The only theory that explains all the data.
Theory: Other Blennerhassett ancestry.
- Summary of theory:
- We descend from some unknown Blennerhassett line.
We will never find it.
- For this theory:
- It is what you expect if you find people with some undefined "Blennerhassett" ancestry.
You expect never to solve it.
For example, many genealogists have worked
on the huge Gortatlea line
and never solved it.
Bill Jehan
never proved his line.
He also collected vast numbers of disconnected Blennerhassetts around the world.
Connecting any of them to the main family is very rare.
Most remain forever disconnected.
- Against this theory:
- Churchtown story: Must be false.
- "Letitia Blennerhassett" story: Must be false.
Unless somehow we find a link to one of the two
known Letitias.
Why remember such an unusual name?
- Who is "A. Blennerhasset, J.P."?
- A bigger problem:
The strong
DNA matches with the 1st Baronet family are
very hard to explain if they are far away.
- The big one: This theory cannot explain the Yielding DNA matches.
Theory makes no sense.
We all have Robert Blennerhassett's DNA
We have proved that we all (in our family) descend from
Robert Blennerhassett and Frances Yielding.
Robert must be great-grandfather (or maybe great-great-grandfather) of George Cashel.
Therefore 1/256 (or maybe 1/512) of my DNA is from him.
This is a
lot of DNA. I have definitely inherited DNA from him. We all have.
Put another way, the Blennerhassett DNA you inherit is
much bigger than the Blennerhassett DNA you can match with a cousin.
So we all have DNA from Robert Blennerhassett (died 1765).
I call that as proven.
The DNA says we descend from
Robert Blennerhassett and his wife.
There is no candidate for a
daughter to have a runaway marriage.
The most likely theory is a natural child of one of Robert's
male Blennerhassett descendants.
That child is then George Cashel, or his ancestor.
The candidates for the father of a natural child are:
It is probably pointless speculating.
We just must look into the lives of all these men and see what happens.
But we have proved that it is this family somewhere.
Let us summarise our proof:
