Gisors, the keeper of the Templars' treasure?
King Louis VII gave the castle to these knights in 1158: the legend said they buried their wealth somewhere in the fortress! The castle was founded in 1097, when Guillaume II Le Roux ("William the Red"), king of England, William the Conqueror's son, asked the famous engineer Robert de Bellesme to raised him a stronghold. He built a wooden keep on a 20 metres high artificial hill, between Normans and Capetians territories, on a strategical place.
In 1124, Henri I Beauclerc, Guillaume II's brother, extended the surrounding wall and raised a stony keep. At that time, kings of France and England fought over Normandy, but soon, France get back this part of Norman land. Henri II of England seized again the fortress in 1161 and raised a new dwelling. In 1193, king of France Philip Augustus seized Gisors: he added a new keep and new towers.
After the Hundred Years War, Charles VII restored the fortress and the surrounding wall, but in vain... the famous Sully, Henri IV's minister, razed all the old French medieval fortresses in 1591...