Can I have an agreement that this Marchese (William) Guglielmo is the 2nd son of Bonifacio del Vasto and Agnes de Vermandois, daughter of Hugues de Crepe, brother of King Philip I, of France? Guglielmo died after 1160. He was ancestor of Lancia and di Busca families. There is not a specific date of Guglielmo birth year.
