William FitzEmpress (22 July 1136 – 30 January 1164) or William Longespee was the youngest of the three sons of Empress Matilda and Geoffrey Plantagenet, Count of Anjou. His brothers were Henry II of England and Geoffrey, Count of Nantes. Early life William Fitzempress, also known as William of Anjou, was born in 1136, the third and youngest son of Count Geoffrey V of Anjou and his wife, Empress Matilda, the daughter of the late English King Henry I of England. He was born in the time known as The Anarchy, an 18-year civil war that disputed the succession of the English crown between his mother Matilda, the late king's daughter, and her cousin Stephen of Blois. William would have seen little of either of his parents, for, while his father fought in Normandy, his mother campaigned in England. William's eldest brother, Prince Henry Curtmantle, would also join the campaign at age 14 in 1147 (when William was still 11). Henry would later be made Duke of Normandy in 1150 by their father, after the latter had subdued the duchy. In 1151, Count Geoffrey died suddenly at age 38, leaving his wife and three teenage sons, with Henry becoming the new head of the Angevin Dynasty. According to the deceased Count's will, Anjou would go to Henry until he became King of England, upon which the second brother, Geoffrey, Count of Nantes, would receive Anjou. The war would continue until 1153, when the aging Stephen, now around 61 years old, came to an agreement with William's eldest brother Henry that respected Stephen's right to reign for the rest of his life but on the condition that the young Henry be his successor. Stephen would die a year later, in 1154, and William's brother would become King Henry II of England. Career In 1156, aged 20, William was with his brother Henry at the siege of Chinon. This siege was occasioned by the rebellion of their brother Geoffrey. He also conducted the siege at the castle of Mountreuil-Bellay. While doing so he had the writings of the Roman military theorist Vegetius read to him; he then did what Vegetius had done, and the siege ended the next day. In September 1155, King Henry held a council at Winchester where he enthusiastically considered invading Ireland and giving it to William, making him king. The plans were abandoned when their mother, Empress Matilda,