William IX, Count of Poitiers
William, Count of Poitiers was the first son of King Henry II of England and Duchess Eleanor of Aquitaine.
William is reported to have died either at the age of 2 in April 1156, or at the age of 3 on 2 December 1156, after suffering a seizure at Wallingford Castle. He was buried in Reading Abbey at the feet of his great-grandfather Henry I.