Feudal hierarchy system was a political, social and economic system in which land owners rented their land, also known as fiefs to other people of lower status in exchange for loyalty, military services and rent. The hierarchy started to exist as every person having land started to give away certain part of his land, and was rendered services in return of the land.
In this way, the class having largest areas of land was on the top, and then were the people who owned lesser land than the above placed counterparts, and more than their counterparts placed beneath them in the hierarchy. It resulted in a pyramidal structure of society with various levels. Every level in the hierarchy had its own set of privileges and duties that were to be performed.
The hierarchical structure was arranged in such a format that every category of people on the upper level had more privileges & the level of command then the category following it on the lower level. The king was chief commandant and all the land in the area belonged to king at original. The kings distributed their grants of lands, often known as fiefs to his noblemen.
The noble men were the category of people that existed below the king in the feudal hierarchy. In exchange of land, king was offered services by these people. The usual services included supply of soldiers at the time of war. Land loyalty and service were the three important pillars of the feudal society where anybody who took land from king was required to take oath to serve the king with loyalty. Kings were also used to retain large estates of lands with themselves to get royal revenues from them. They also used these lands for hunting etc.
The classes in the feudal hierarchy system were on the basis of the privileges that it held and the duties it was required to perform. Every class had a set of duties, and in this way these small kingdoms became self-dependent. These kingdoms had every type of people required to perform every type of job. The lands were distributed to get the services, and hence people owning larger lands started getting respects from the ones who held small areas of lands.
The uppermost class was of the King and lowermost class was of peasants who were responsible to grow crops and farm the lands. This class system was initially adopted to fight the external problems that the people of Europe were facing, but later on it became hereditary and started posing its own problems. Problems involved that people of lower classes were treated badly; rich were becoming richer while poor were becoming poorer. People of one class cannot take up jobs of their interest; rather they were forced to perform the duties of the class in which they were born.
During 18th and 19th centuries, the wind of change bowled and as a result of many revolutions the feudal system also saw its end.