Caen was a settlement already in Roman times, but prospered, when
William the Conqueror (aka "William the Bastard") built a castle here. When William married Matilda of Flanders (~ 1051) a papal ban was issued at the Council of Reims on the grounds of consanguinity. In 1059 Pope Nicholas awarded dispensation, after William and Matilda agreed to found to monasteries as penance.

William founded the Abbey of Saint-Etienne (aka "Abbaye aux Hommes"), Matilda founded the Abbey Sainte-Trinité (aka "Abbaye aux Dames"). The erection of both abbeys started in Caen around 1060.

The "Abbaye aux Hommes" was suppressed during the French Revolution, the Benedictine monks left. The church became a parish church after the revolution.

The windows around the choir may be "reconstructed" copies of the medieval originals, as during the Battle of Normandy in WW2 an intense bombing campaign destroyed much of the city and severely damaged the cathedral.
At that time many inhabitants had sought refuge here.

Here is the Adoration of the Magi.