He would be your great great uncle, but you could call him whatever endearing name you both prefer.
my great grandfathers brother or my great uncle
I believe you would call them your great great uncle.
Your grandfather's brother is your great uncle.
Your grandfather's uncle is your great great uncle. Your grandfather's brother would be your great uncle
Your grandfathers brother to you is your Great Uncle!
Your father's grandfather is your great grandfather.
My great great second, half, brother in law who's great great grandfathers....son.
Your Grand Uncle(great uncle) would be your grandmother or grandfathers brother.
Your great grandmother's brother is your great great uncle.
Your father's brother is your uncle. Your Grandfather's brother is your great uncle. Your Great Grandfather's brother is your great great uncle.
Your grandfather's brother is your great uncle.
Your grandfather's brothers would be the uncles of your parent. That would make them your great uncle.
You would be second cousins.
They call him "Great Uncle (his name)."