The basic social and political unit among barbarian groups was the tribe or confederation, a group whose members believed that they were all descended from a common ancestor and were thus kin. Tribes were led by chieftains. The chief was the member recognized as the strongest and bravest in battle and was elected from among the male members of the most powerful family. He led the group in war, settled disputes among its members, conducted negotiations with outside powers, and offered sacrifices to the gods. The period of migrations and conquests of the Western Roman Empire witnessed the strengthening of the power of chiefs, who often adopted the title of king, though this title implies broader power than they actually had.

Closely associated with the chief in some tribes was the comitatus, or war band. These warriors swore loyalty to the chief, fought with him in battle, and were not supposed to leave the battlefield without him; to do so implied cowardice, disloyalty, and social disgrace. These oaths of loyalty were later more formalized in the development of feudalism (see “Decentralization and the Origins of ‘Feudalism’” in Chapter 8).

Although initially a social egalitarianism appears to have existed among members of the comitatus because they regarded each other as kin, during the migrations and warfare of the third and fourth centuries, the war band was transformed into a system of stratified ranks. Among the Ostrogoths, for example, a warrior nobility evolved. Contact with the Romans stimulated demand for goods such as metal armbands, which the Romans produced for trade with barbarian groups. Armbands were of different widths and value, and they became a symbol of hierarchy among warriors much as the insignia of military rank function today. During the Ostrogothic conquest of Italy, warrior-nobles also began to acquire land as both a mark of prestige and a means to power. As land and wealth came into the hands of a small elite class, social inequalities within the group emerged and gradually grew stronger. These inequalities help explain the origins of the European noble class.