The Anglo-Saxon kingdoms were hierarchical societies, each based on ties of allegiance between powerful lords and their immediate followers. At the top of the social structure was the king, who stood above many of the normal processes of Anglo-Saxon life and whose household had special privileges and protection. Beneath the king were "thegns", nobles, the more powerful of which maintained their own courts and were termed "ealdormen". The relationship between kings and their nobles was bound up with military symbolism and the ritual exchange of weapons and armour. Freemen, called "churls", formed the next level of society, often holding land in their own right or controlling businesses in the towns. "Geburs", peasants who worked land belonging to a "thegn", formed a lower class still. The very lowest class were slaves, who could be bought and sold and who held only minimal rights.