A grandfather is not a father-in-law if the parents (one of whom is a child of the grandfather) are not married.
Your Grand father's Grandfather5's Grandfather's Grandfather's Grandfather's Grandfather's Grandfather's Great Grandfather created History.
The term is hyphenated, as great-great-grandfather(grandfather's grandfather).
The singular possessive form of the word "grandfather" is "grandfather's."
Your great great grandfather.
Your grandfather's father is your great grandfather.
Your father's grandfather is your great grandfather.
Your grandfather's father is your great grandfather.
Your grandfather's father is your great grandfather.
He is your Grandfather, and is your son's Great-Grandfather.
He would be your paternal great grandfather
Your great grandfather's nephew was your grandfather's first cousin. You are two generations removed from your grandfather and his cousin. Therefore you and your great grandfather's nephew are first cousins, twice removed.
Great-Grandfather.