Most people enjoy looking at ancient castles. Sometimes they are gaunt and desolate storm-beaten ruins upon which the wind and the rain have exerted their fury unresisted for generations. Castles were introduced into the country by the Normans. Everyone knows how that race of mounted, mail-clad warriors came over under their leader, William the Conqueror, and struck down the English at the Battle of Hastings in 1066; how William had himself crowned King of England, and very soon overran the whole country. These Normans brought with them the system of government called feudalism; and to understand what a castle was, one must understand this system of feudalism. Feudalism of course gave the landlords great power over their tenants; and under a weak king, the feudal system often resulted in bitter oppression of the small man by the great man. Of this new system the castle, as the private stronghold of a feudal baron, was the visible symbol.