The estates of the realm were the broa divisions of society, usually distinguishing nobility, clergy, and commoners recognized in the Middle Ages, and, later, in some parts of Europe. While various realms inverted the order of the first two, commoners were universally tertiary, and often further divided into burghers (also known as bourgeoisie) and peasants, and in some regions, there also was a population outside the estates. An estate was usually inherited and based on occupation, similar to a caste,