William V of Aquitaine (969-January 301030), nicknamed the Great, was Duke of Aquitaine and Count of Poitiers as William II of Poitiers. William was the son of William IV of Aquitaine by his wife Emma of Blois. He married three times and four of his five sons ruled Aquitaine after his death. Through his descendant, Eleanor of Aquitaine, he is an ancestor of the present-day British royal family.
