The Middle Ages was an era of great decline in Europe that lasted from 500 AD to 1400 AD following the collapse of the Roman Empire. Many refer to the early Middle Ages as "The Dark Ages" because of the poor living conditions and structure the people of this era had. During this time, vikings were busy invading much of Europe, and tribal disputes lead to war. However, as time progressed, the people of the Middle Ages were able to created a structured sort of hierarchy called the Feudal System. The Feudal system brought many changes and improvements to the lives of the people living in this time, and was a large stepping stone that helped lead Europe out of the Middle Ages. A major component within the Feudal system was the manor. A manor was a large amount of land given to a lord by the king in exchange for a military. The manor, also refereed to as a fief, contained a large castle that provided housing and protection for peasants and knights living within the fief. In exchange, peasants and knights provided a manor its food supply and protection. Each hierarchical level within a fief was co-dependent on another, and in this way the Feudal System acquired stability and stuck around.
During the times of the Roman Empire, farmers had a system that gave them four bushels of grain for every one that they planted. This ratio of 4:1 dropped to 2:1 due to the poor farming techniques the peasant farmers had adopted from the Mediterranean. This low ratio demanded about half of a harvest's yield be used as seed for the following year. This led to very low amounts of food, and in years where harvests were bad, famine resulted. As it is with any civilization, the key to a successful and prosperous Feudal System was food surplus and stability, and with the Agricultural Revolution came just that. Food was grown within each fief by those in the lowest level of a Fiefdom's Hierarchy, peasants and serfs.