The primary consequence of the Feudal System in medieval society was the creation of a hierarchical structure that defined social, economic, and political relationships. Land was held by lords, who granted portions to vassals in exchange for military service and loyalty. This system led to a localized economy with peasants working the land in return for protection and a share of the produce. Overall, feudalism created a fragmented society, where power dynamics were heavily influenced by land ownership and personal allegiances, resulting in limited social mobility and often instability.