Final answer:
The Feudal System is the political organization system introduced by William the Conqueror in England. It was characterized by a hierarchical structure and played a significant role in medieval England.
Step-by-step explanation:
The system of political organization that William the Conqueror brought to England is known as the Feudal System. This system was characterized by a hierarchical structure where the king owned all the land and granted portions of it to lords or nobles in exchange for their loyalty and military service. The lords, in turn, granted land to vassals who pledged their allegiance and provided military support. This system provided a framework for social, economic, and political relationships in medieval England.