Answer:
Feudalism
Explanation: Feudalism started to happen when the people didn't trust the kings anymore, and created a system of their own. Lords would give land to vassals(aka knights) and peasants for their service. So, the lords give the vassals a place to live and food to eat, while the knights protected the lords from invaders. The lords mainly gave peasants food and a place to live, and a small amount of land for their work around the manor.