foederati

Foederati are a term used for military allies in the late Roman Empire. The word comes from Latin foedus, treaty. Foederati were non-Roman tribes and peoples bound to Rome by formal agreements to provide military service in exchange for benefits such as land, rations, subsidies, and protection.

The alliance often placed groups within or near Roman territory as settled communities. They kept some internal leadership and customs but were integrated into provincial structures; they supplied troops, sometimes entire contingents, to the Roman army and frontier defense.

The foederati system allowed Rome to supplement manpower when legions dwindled. Groups such as the Visigoths, Vandals, Ostrogoths, and other Germanic peoples entered as foederati at various times. The arrangements could be stable for years but frequently unraveled, as groups demanded broader concessions, clashed with Roman authorities, or asserted independence, contributing to political crises and the eventual transition from the Western Empire.

In historiography, foederati illustrate Rome's shift from direct citizen recruitment to federated allied groups to maintain military capacity. The term describes a diplomatic and military tool rather than a single uniform policy, reflecting the empire’s evolving relations with neighboring societies in late antiquity.