When great grandparents are related

[brigidmac]

I've got a chance to look at a concrete example which might effect DNA cm amounts

DNA results just in but I think I can see high DNA matches to some descendants of
Thomas B.+ Eliza H


Caroline Ann  C... (nee B.)’s father
Thomas John B was a brother of Eliza Caroline B, wife of Alfred C
. Eliza Caroline was born in Kensington in 1866 and Thomas John was born in Chelsea in 1871.
Both were children of Thomas B. Cab Driver and Eliza Nee H

This means that Caroline + Alfred C.... s son  Eric Alfred C..’s paternal grandmother and maternal grandfather were brother and sister.

I'm looking at DNA matches for their child

Ive used initials for  surnames for privacy reasons

But will be able to compare results with anyone who has a similar scenario.
Ps the 2 great grandparents in this case are both from paternal side

[ALAMO2008]

That is not as unusual as you might think.
It happened in my Paternal Ancestors born in 1890s
One Daughter married her Mother's Youngest Brother
One Child Died at Birth
The other Son was Not normal though lived.

[brigidmac]

It's very common in small communities .
It's also common among Jewish community
& LDS

 This is the closest example I've got in someones tree whose DNA I manage so it will be very useful to compare DNA matches if descendants.

Especially for someone else  who's birth father I'm identifying + already know that some of the matches have second cousin marriages in their lineage.

Alamo have you done DNA test ?

[ALAMO2008]

Yes
Finally got around to a DNA test which I resisted for years for some unknown reason.
Now got 400 Cousins
In touch with about 20

My Great Grandfather came to Liverpool from Dublin
His Father was a Corkcutter
Found a Corkcutter Same Name as his Dad
I had a Theory that he was the older brother who came over to Liverpool first that Great Grandfather followed over.
Could never prove it or convince my Cousin of my Theory.
That Corkcutter converted to Mormon and emigrated to Salt Lake City in 1880s
Just been contacted "out the blue" by his Great Grandchildren who found Our DNA matched .
Proving they were Brothers with the Same Dad Corkcutter in Dublin
DNA proved my Theory

[brigidmac]

Yes that's what I'm finding too .I now manage 3 generations of DNA + some of my mother's 2ndhalf C  too
The DNA relationships suggested by ancestry   invariably fit with top suggestions to our knowledge on  paper work . Except where there's been an adoption or double connection

I've only recently come across Mormons not my direct relations but really good research it's part of the culture and when you find the common ancestors 100s of thru lines show up . I find quite a small percent have mistakes in their trees .

Well done for following your hunch .

[ALAMO2008]

https://www.pbs.org/mormons/etc/genealogy.html#:~:text=Mormons%20trace%20their%20family%20trees,strengthen%20the%20eternal%20family%20unit.

[melba_schmelba]

It's very common in small communities .
It's also common among Jewish community
& LDS

I am not even sure 'small communities' was required. I have several examples in people who don't fit that description. I think people were more suspicious of non family members in those days, and an unmarried family member was seen as a 'safe' match for perhaps those who hadn't married by 25. But have also seen the phenomenena of widowed men marrying their cousins soon after losing a wife. Basically a marriage of convenience for someone to look after the children or/and the household. Last cousin marriage I can find is the 1930s. Probably it happened less simply because people moved about a lot more later on.

[brigidmac]

You're right Melba and of course meeting at a wedding was common.
Old maids song  with Scottish accent
" Oh I've often heard it said fra me mother and me faither
That the gang (going) to a wedding is the making of another..
Iffen that be so will you hai me to your wedding

...

[brigidmac]

Re original post

Thru lines have just come up on ancestry
To gson of Alfred ( but are rearranging themselves due to some tree changes )

ALFREDs C  grandmother s brother  married grandfathers sister

Any descendants of Thomas B the cab driver and Eliza H
would be  shared great grandparents  TWICE Alfred  2nd cousins thru 2 different lines .

Alfred has  only have 6 great grandparents

But will this make a DIFFERENCE at 4th C level

And WILL thru lines show both connections ?

Will double check all suggested matches and let you know