I. - MEDIEVAL

In Europe in the Middles Ages the castle was a fortified residence of a nobleman, effectively displaying his authority and feudal lordship over the territory associated with it as well as serving a military function. The castles were sometimes fortified towns with a fortified bridge which was very important against the defense of the Vikings.

The earliest known castle is in the Loire Valley in northern France at Doue-la-Fontaine dated 950 and it is were feudal society originated.

Doue-la-Fontaine