William VII of Aquitaine, (Pierre-Guillaume in French) (1023 – 1058) was the Duke of Aquitaine and Count of Poitiers as William V of Poitiers between 1039 and 1058, following his brother Otto of Aquitaine. William was the third son of William V of Aquitaine by his wife Agnes of Burgundy. He was brother-in-law of Henry III, Holy Roman Emperor who married his sister Agnes de Poitou. He married Ermesinde of Longwy (daughter of Adalbert of Longwy, duke of Lorraine) and had two daughter's, Clementia, who married Conrad I of Luxemburg and Stephanie.
See also: Dukes of Aquitaine family tree
