William III (913 – 3 April 963), called Towhead (French: Tête d'étoupe, Latin: Caput Stupe) from the colour of his hair, was the "Count of the Duchy of Aquitaine" from 959 and Duke of Aquitaine from 962 to his death.
The primary sources for his reign are Ademar of Chabannes, Dudo of Saint-Quentin, and William of Jumièges.
Shortly after the death of King Rudolph in 936, he was constrained to cede some land to Hugh the Great by Louis IV.
His father was duke Ebles Manzer, who already was a man in his middle years when William was born in about 913.
According to the chronicle of Ademar de Chabannes, William's wife was Geirlaug (French: Gerloc, also known as Adèle), a daughter of Rollo of Normandy.