William III Count of Ponthieu

William III Count of was born in 1179 in Ponthieu, France.  William III Count of's father was John I Montgomery Count of Ponthieu and his mother was Beatrice Candavaine de St. Pol. He had a sister named Adele de.  He was the younger of the two children.  He died at the age of 42 on October 4th, 1221 in France.

‌William III Count of and Alix Princess of were married in a religious ceremony on August 20th, 1195 in Meudon, France.  They had a daughter named Marie Countess of.