During the Middle Ages, four separate and distinct castes emerged from the social institution of Feudalism. These were: the nobility, the clergy, the peasants, and the burghers or townspeople. The most powerful classes were the nobility and the clergy, but the burghers (mostly merchants and artisans) saw their numbers and influence increase significantly during that time. Most people still belonged to the peasant class, however, and had little social mobility.
As Feudalism was based upon the ownership of land, the nobility, who also monopolize military force, exerted a great deal of control on the rest of society. Given the fact that this caste controlled much of the economic and military resources of their time, it may seem illogical that they often willingly subjected themselves to the clergy. They did this because the clergy had managed to make themselves brokers of salvation, thus making them the First Estate. In a time as prone to disease, famine, and war as the Middle Ages, those who hold the keys to ones eternal salvation can and will command respect. True, the nobility and the clergy, especially in the later middle ages, often fought for power, but in most cases, the nobility eventually submitted to the will of the Pope and his ever growing bureaucracy.
Unfortunately, the great deal of power that the clergy wielded in pre-Reformation Europe corrupted many of its members. As the Church increased its wealth and even asserted secular power for itself, some began entering the clergy for less than pious reasons. Partly because of the principle of primogeniture (which stated that the eldest son received the whole inheritance) many second-born sons sought positions in the church. Thus, simony (the buying and selling of church offices) became almost as much of a money making practice for the church as the sell of indulgences. Since many of the clergy were in the church for secular reasons, the institution of the clergy itself became exceedingly corrupt in the pre-Reformation Era. Immorality, greed, pluralism, absenteeism, and ignorance were just a few qualities which critics found in many members of the clergy.
Although they exerted the most control over life during this time, the nobility and the clergy were not the only two estates exerting their own pressure upon society. With the Renaissance came an increase in trade with began to slowly break down the institution of Feudalism. By the 16th century, a new merchant class, usually urban, had grown to the point that it could rival the nobility who found their economic condition worsening during this time. The nobility found themselves having to rely increasingly on the merchant class for economic and political support while the peasant class witnessed the benefits of a small amount of social mobility.
This peasant class, which represented the vast majority of people during the middle ages were mostly uneducated agricultural workers who worked the land for a feudal lord in exchange for protection. Although they were not slaves, they had few rights a few opportunities for advancement. As Feudalism slowly broke down and the merchant class grew, however, that slowly began to change.
References
Wikipedia
History on the Net
The Internet Medieval Sourcebook
