William was born in Falaise in 1027. The illegitimate son of Robert the Magnificent, Duke of Normandy, and Arlette, daughter of a tanner, he was nicknamed "the Bastard". After the death of his father when William was 8, he became Duke of Normandy but the Norman barons revolted against him, joining forces against this young master of the duchy.

At the age of 20, William definitively established his power in the province, after his victory over the rebels in Val-ès-Dunes (near Caen). He then decided to make Caen a strategic site and main place of residence.

Around 1050, William married Matilda of Flanders, his distant cousin, going against the wishes of the Pope. To obtain the Church’s pardon, at the same time as building the mighty Caen Castle he built two abbeys: the Men’s Abbey and the Ladies’ Abbey.

Across the Channel, as the King of England neared the end of his life, he appointed William, his cousin, as his successor. However, the Saxon Harold, betraying the promise made to William, was crowned. In the face of this felony, William armed an invasion fleet and defeated Harold at the bloody Battle of Hastings (depicted in the Bayeux Tapestry) in 1066. "The Bastard” became “The Conqueror” and was crowned Kind of England in Westminster.

Four years after Matilda, William died in Rouen in 1087. They were both buried in Caen in the abbeys they founded: William at the Men’s Abbey and Matilda at the Ladies’ Abbey. Their descendants reigned over the Anglo-Norman kingdom until 1204, when Normandy was annexed by the King of France.