William IX, Count of Poitiers
| William IX | |
|---|---|
| Count of Poitiers | |
| Reign | 17 August 1153 – 1156 |
| Born | 17 August 1153 Normandy, France |
| Died | 1156 (aged 2/3) Wallingford Castle, Berkshire |
| Burial | Reading Abbey, Berkshire |
| House | House of Plantagenet |
| Father | Henry II of England |
| Mother | Eleanor of Aquitaine |
William IX (17 August 1153 - April/December 1156) was the eldest son of Henry II of England. He was heir to the throne from his birth to his death in 1156.