man in USA another in UK both had single greatgrndmothers ) same g grandpa ,??

[brigidmac]

Title and wording changed because confusing ..apologies

                 °I think my grandfather's birth father is  Your grandfather s birth father too "

How would you feel if you got a message like that ?

How probable is it to find proof without the name of the man in question ?

When there are no shared surnames in common .

Its barely conceivable even for DNA buffs....

But ..
           by a series of luck,
                                             hunches .
+ elimination (ethnicity ,locations & other shared matches)

Today

I am the person sending that message to a   potential  half second cousin

[brigidmac]

 (Its actually my UK cousins DNA who matches American ...on their respective fathers side s

Also its the highest match on his father's side  115cm across 5 segments

 at that level
estimate one shared great grandparent

Immediately  I eliminated the 4 maternal great grandparents he shares with me.
 All their mutual thru lines are established

1) ETHNICITY
His Match is half italian 2 grandparents are italian

So eliminate 4 of their great grandparents too

The main match of ethnicity for the British man & the American  is;
 English 34 percent and 26 percent respectively

Cousin has 12percent irish from paternal grandmother s mother
Match has zero irish  so we.ll rule out Irish grandmother  too


2)NAMES

No surnames in common but both have grandfathers born to single mothers

.surname of greatgrandfather unknown

Not enough proof yet ....?

See part 3

[brigidmac]

3) LOCATION

American"s paternal grandmother and her parents born & lived in Canada

So we can also rule them out

American s grandfather was born in Southshields Durham .1892.  .

The....only person  on his tree with a location match

he moved to USA as an adult and was naturalized in 1917


My Cousins paternal grandfather born Stockton on Forest 1902 Yorkshire


His mother ( the great grandmother)lived all her life in Yorkshire

Southshields is certain closer than
  Canada .

Their closest mutual match at 67cm level to my cousin
Has a tree with all great great grandparents.born in Yorkshire



4)PROFESSION

Both their great grandmothers in domestic service

5) other CLUES
Both named their sons John !

Feel very lucky to establish this connection .

 Would welcome opinions or similar experience s &  Advice about follow up steps

[brigidmac]

I see some other posts about finding unknown great grandfather s

Will these steps help anyone else ?

Another tip is not to rely entirely on DNA

 look for affiliation orders school records and baptisms too

[brigidmac]

The only.downside is

My cousin.wanted to know about his grandfather
and we.ve found far more about his grandfather s America half brother

He now has photos of some of his  half first cousins once removed and doesnt have photos of his own grandad or the British half uncle he knew when younger

[brigidmac]

The match.is now showing up on thru lines

Does that mean.they.have also.added the great grandfather
 
Or are they getting a green box suggestion.of great grandfather
"John.UNKNOWN "