William I died on 9 September 1087 at the priory of St Gervase near Rouen, ending a reign that had begun with his conquest of England 21 years earlier.

William had left England for the last time in 1086. The following year, he campaigned in the French Vexin after disputes with Philip I of France. During an attack on Mantes, William became seriously ill or was injured. Accounts differ over exactly what happened. One tradition says that his horse stumbled and the pommel of his saddle caused an internal injury.

They took him to Rouen and then to the nearby priory of St Gervase. Before his death, William arranged to divide his possessions rather than hand them intact to one heir.

His eldest son, Robert Curthose, received Normandy. William Rufus, his second surviving son, crossed to England and succeeded his father as William II. Henry, William’s youngest surviving son, was left £5,000 in silver. He would later become Henry I of England.

William’s body was taken to Caen in Normandy and buried in the abbey church of St Étienne, which he had founded.