Little is known about how nobility first developed. Tacitus already said that there used to be a time when all humans were equals and that hereditary peerage didn't exist until "they began to throw off equality" (Tacitus, Annals 3.26). In places where no written sources are available, archaeological findings indicate that graves with very extravagant burial goods are located right next to graves with exceptionally simple burial goods. Archaeologists refer to graves with ornate burial goods as princely tombs even though nothing is known about the power structure due to the lack of written history.
All societies that belong to the category of advanced pre-industrial civilisations have a noble class. Typically, nobility stands out because noble families have more influence on public events as well as a greater economic potential than the majority of people. As a consequence, they also serve as decision-makers in military and political matters that affect their (economically dependent) neighbours. Despite the fact that the superior position was originally based on economic factors, it was usually passed on from one generation to the next.
In the different regions of the world, this hereditary rule is justified in two different ways: In the case of clerical nobility, people often believed there was a special relationship between the Gods and chosen individuals. In the case of knights, samurai and other military nobility, their higher status was based on the individuals' military achievements or superiority. Economic superiority – which landowners of particularly large tracts of land may enjoy – often entitled individuals to exercise power over others. High-ranking persons such as kings and emperors had the right to confer nobility.