From the Wikipedia page 
John of Vaudémont (died 1473) was a younger son of Antoine of Vaudémont and Marie of Harcourt.
His mother was the eldest daughter of John VII of Harcourt, Count of Harcourt and Aumale, and after the death of her brother John VIII of Harcourt in 1424, her father's heir. In anticipation of this, she assigned to John the County of Harcourt in 1448. In 1449, at the breakdown of the Truce of Tours, he was sent as an ambassador to the Duke of Burgundy by King Charles VII.
In 1452, his maternal grandfather died. John attempted to secure the whole inheritance for himself and his mother. While briefly effective, by 1454, his mother's younger sister had gained control of the County of Aumale.
He was appointed captain of Angers in 1469, and later seneschal and governor of Anjou. He died in 1473, unmarried, and was succeeded by his nephew René II, Duke of Lorraine.