foederati

Foederati ( ; singular: foederatus ) were peoples and cities bound by a treaty, known as foedus, with Rome. During the Roman Republic, the term identified the socii, but during the Roman Empire, it was used to describe foreign states, client kingdoms or barbarian tribes to which the empire provided benefits in exchange for military assistance. The term was also used, especially under the empire, for groups of barbarian mercenaries of various sizes who were typically allowed to settle within the empire.

==Roman Republic== In the early Roman Republic, foederati were tribes that were bound by a treaty (foedus ) to come to the defence of Rome but were neither Roman colonies nor beneficiaries of Roman citizenship (civitas). Members of the Latini tribe were considered blood allies, but the rest were federates or socii. The friction between the treaty obligations without the corresponding benefits of Romanity led to the Social War between the Romans, with a few close allies, and the disaffected socii. A law of 90 BC (Lex Julia) offered Roman citizenship to the federate states that accepted the terms. Not all cities were prepared to be absorbed into the Roman res publica (Heraclea and Naples). Other foederati lay outside Roman Italy such as Gades (Cádiz) and Massilia (Marseille).