What are Benefits? Why was the owner of the benefice dependent on the king?

Benefits have spread since the reign of Karl Martell in the Frankish state. Benefit should be understood as a piece of land that was given to a person in exchange for his service to the royal court (whether it be administrative, military, or court service). As long as the terms of the contract were respected, the land belonged to the franc, but if the conditions were not fulfilled, the land passed to the owner. Benefits can be seen as the forerunner of the feudal fiefs. Benefits were mainly owned by knights who marched on the orders of the king.