In return, the lord has to maintain the land of vassal and might give the vassal employment under the mutual contract. Also, the land received by the vassal allowed the vassal to have a place to live and make a living. During the Middle Ages, the three groups of people were the people who fought, people who worked and people who prayed. Feudalism organized society into a pyramid structure that consisted of different social classes where people stayed in the same social class their whole lives and their children would inherit the same social class. At the bottom of the pyramid were the peasants who were landless, worked in the field and the majority of the population. Most of the peasants were serfs who were legally required to stay on the land where they were born. All of the revenue the serfs produced was the property of the landowner. Above the peasants were the knights, horsemen who defended the lands of the lords and received fiefs. Above the knights were the wealthy landowners including bishops and nobles and on top was the king. Overtime, fiefs grew larger and wealth was judged based on land and