Normans/Frenchmen invaded. William imposed Norman law, government and language on Anglo-Saxons.
Foundation of Norman civilization (Feudal System) which was based upon the holding of land. King owned all the land; he granted areas to his lords who promised him their services. Lords gave portions to the knights who pledged to assist them in battle. Serfs were the lowest on the social scale. Paid goods and services to the lord in return for land they farmed. (conquered England)