Final answer:
William's conquest of England led to the establishment of feudalism, the building of castles for control, and transformed the country's political landscape, especially during the Tudor dynasty under Henry VII.
Step-by-step explanation:
The long-term effects of William taking control of England included the establishment of feudalism, which was a social system that emerged from the need for security and was characterized by unequal relationships. Lords would provide land called fiefs to vassals in exchange for military service and loyalty. This structure was largely due to the absence of effective government forms and the need for protection against raiders. William the Conqueror built many castles to maintain control and order, significantly shaping the medieval societal structure in England. William was not dethroned; instead, England experienced a shift in power dynamics during the War of the Roses and, later on, during the Tudor dynasty, the monarchy became the primary political force, especially under the rule of Henry VII.