Theory of O'Connell descent
I have formed a speculative theory that my ancestor
George Cashel (born 1807)
may descend from the O'Connell family,
the family of
Daniel O'Connell, "The Liberator"
and his wife and cousin
Mary O'Connell.
This theory is very far from proved.
But there is enough initial evidence to look at it at least.
Background: George Cashel descends from Blennerhassett
The background is that my ancestor
George Cashel
emerged in some irregular way from the landed gentry Blennerhassett family of Co.Kerry.
This was already known by my family, but it took decades to prove
that he is in fact closely related to the Blennerhassett Baronets family.
See the
proof
from documents and DNA
that he must descend somehow from
Robert Blennerhassett (died 1765),
father of
Sir Rowland Blennerhassett, 1st Baronet.
The most likely theory is that
George Cashel is the natural son of one of the 5 sons of the 1st Baronet,
or maybe the natural son of their 1st cousin
Robert Arthur Blennerhassett.
Something irregular happened.
One imagines it would be the old story:
A wealthy Blennerhassett man has a brief affair with a lower class woman,
and then leaves her with the baby.
However, this page suggests something much more exotic may have happened:
A wealthy Blennerhassett man has an affair with a woman of his own class.
Let us lay out the evidence so far.
Unexplained DNA matches
The theory begins with
Sheila O'Connell,
who has strong, unexplained DNA matches with multiple parts of the family below
George Cashel.
- Sheila O'Connell is a
DNA match (through unknown line) of (Blennerhassett Cashel, 1st marriage):
and of (Blennerhassett Cashel, 2nd marriage):
and of (Cashel of Alaska line):
- These DNA matches are pretty big. They indicate a common ancestor around 1800.
- The DNA matches do need explaining. But this by itself is not unusual.
Lots of DNA matches need explaining, and often are never explained.
- Normally I would not start with DNA matches and search for an explanation, because you never find one.
I go the other way. Construct a theory and then see if DNA matches support it.
- However, this one is different.
Systematically going through all shared matches groups
of all my people
on Ancestry suggests
Sheila O'Connell as the strongest unexplained group of matches in all my George Cashel descendant accounts.
So it is worth a closer look.
- How could we be related to Sheila?
We look
first at the Cashel family.
The DNA matches are spread across different sons of George Cashel
(and two different wives of one of the sons),
so therefore
the common ancestor must be through either George Cashel (Co.Kerry) or his wife (Co.Tipperary).
- Then looking at Sheila O'Connell's ancestors, it seems
the match must be through either the
O'Connell or Leyne lines,
both in Co.Kerry.
The likely lines (O'Connell and Leyne) are linked to Blennerhassett
- The next step is that we see that Sheila's ancestors through O'Connell and Leyne
are deeply connected with Blennerhassett both socially and by blood.
This is now starting to look interesting.
- First, by blood. She actually descends in
two different lines
from early, 17th century Blennerhassetts.
But that is too far back to
explain the strong modern DNA matches.
The common ancestor must be more recent.
- She does not apparently descend from the Blennerhassett Baronets branch in any way.
So that is not the answer to the DNA matches.
- This raises the extraordinary possibility that
this is George Cashel's parent
who is not the Blennerhassett Baronets line.
- Have we found the line of George Cashel's mother?
That is, his mother is not a lower class woman.
Instead she is a well-off woman from this branch,
which we know is socially connected with the Blennerhassetts.
She has an affair with a Blennerhassett man from the Baronets branch, and he is George Cashel's father.
O'Connell fits better than Leyne
- Looking at the Leyne line,
it is hard to see how a mother for George Cashel could fit in.
Maurice Leyne, MD, marries in 1786, which is a bit late for him to have a daughter
who is George Cashel's mother.
Maybe Maurice has a niece that would fit.
We will keep looking.
- Over in the O'Connell line, we are looking at the family of
Thomas O'Connell, MD.
The dates and general layout fit much better to have a daughter who
is George Cashel's mother.
- And in fact, there is one interesting candidate:
The unnamed daughter who
married Patrick O'Mara.
What is the source of this?
Why is she unnamed?
O'Connell is linked to the Blennerhassett Baronets
The most exciting piece of evidence is the following:
- We discovered that
Ellen Tuohy, widow of Thomas O'Connell, MD, married in 1803 to what seems to be the 1st cousin of
Sir Rowland Blennerhassett, 1st Baronet.
- This is a breakthrough.
That means that after 1803, Ellen's unmarried daughters are likely to be
socialising with the 1st Baronet's sons.
And hence an affair could happen around 1806.
- Quite a discovery.
This is beginning to look beyond coincidence.
Theory: George Cashel descends from Blennerhassett and O'Connell
Here is a guess at what we think maybe happened.
- Ellen Tuohy marries in 1803 to the 1st cousin of the 1st Baronet.
- Her daughters socialise with the 1st Baronet's sons and relatives.
- A brief affair happens. An O'Connell mother. A Blennerhassett father.
- It may seem strange to suggest that neither parent has surname "Cashel".
But this is where the evidence points.
-
George Cashel is maybe given an invented surname.
This would explain why his descendants do not DNA match any Cashel in the world
- which otherwise is hard to explain.
- An alternative for his surname is that it is from an adoptive family.
But no other Cashel ever turns up in his life, so maybe this is not likely.
- After the affair, the O'Connell mother is maybe quickly married off to O'Mara of Co.Limerick
to get her out of Co.Kerry,
and her first name forgotten?
So in 2025 I formed a possible extraordinary theory that
George Cashel's mother
is the sister of Mary O'Connell who married Daniel O'Connell.
Far from a proof so far.
More work needed.
Against the theory: Why not remember Daniel O'Connell?
One point against this theory is:
Why did my family not remember the close link to
Daniel O'Connell?
Any Irish person would be proud of that.
-
Maybe we have to get into the mindset of
George Cashel.
He was a policeman, and maybe much more keen on connecting to the establishment Blennerhassetts
(after whom he named his son)
than the nationalist Daniel O'Connell,
who was jailed in 1844.
- Although George Cashel seems to have
supported Home Rule late in life,
around 1879.
And the next generation of Cashels for sure would have been interested in the
Daniel O'Connell link.
- If the O'Connell theory is true, it is very strange my family remembered Blennerhassett and not O'Connell.
Mary O'Connell, who married Daniel O'Connell.
Do we descend from her sister?
Daniel O'Connell.
Is he my ancestral uncle?
