Warfare had become endemic in eleventh- and twelfth-century Europe. Castle building used up the resources of the land as every landholder from the ki… - Marilyn Stokstad

The Church attempted to regulate this rather violent society, and eventually a code of honor evolved known as the code of chivalry. (...) Those who aspired to be knights had to have aristocratic ancestors and wealth enough to own warhorses and armor and to provide for a team of supporters.

Women played a greater role than might be expected in this elite warrior society, as heiresses and chatelaines in charge of castles (see Documents 44–53). Since land was the basis of status and power, estates were kept intact by being passed on to the oldest son rather than being divided among all the children. In spite of high infant mortality and short life expectancies, a family hoped that at least one son survived to inherit lands and titles. Younger sons hoped to gain an estate of their own by marrying an heiress.

Never as neat or well organized as many descriptions suggest, in essence feudalism involved the exchange of grants of land for military and political service, sealed by personal oaths between the lord and the vassal. The castle has been called the perfect architectural expression of the European feudal age.