Were allies of Rome. The Roman conquest of Italy resulted in a system of military alliances by which native communities remained theoretically independent but were in practice reduced to subjects. This relationship was enshrined in treaties of alliance (see foedus) which the Italian peoples made with Rome, on terms that were more or less favourable, depending on whether they joined Rome voluntarily or were defeated in war. By the time of the Punic Wars more than 150 separate treaties had been concluded, and all the peoples of non‐Roman Italy had become socii. Although the more equal treaties stipulated military partnership, in practice all the allies were obliged to assist the Romans by sending contingents of troops to fight alongside the legions. These obligations were set out in a document which seems to have defined the number of troops each allied community could be called upon to contribute. During the 3rd and 2nd cents. bc Roman armies always contained a large proportion, varying between half and two‐thirds, of allied troops. In exchange for their contribution the allies received security and a share of the profits of conquest, esp. the right to take part in land assignations and colonies. This doubtless explains the remarkable loyalty of the allies, even when tested to the limit in the Hannibalic War. During the 2nd cent., however, the relationship changed, as colonization ceased and the profits of empire, in the form of regular provincial taxation, were monopolized by Rome. By the time of Marius the system had become exploitative, and in 91 allied discontent gave rise to the Social War (i.e. the war against the socii). This bloody conflict ended when the allies were given Roman citizenship and incorporated in the Roman state.
From early times Rome also had allies outside Italy, notably Carthage and Massilia, and their number increased rapidly after 200 as kings, city‐states, and confederations made treaties with Rome on nominally equal terms. Unlike the Italian allies, they did not regularly contribute troops, although they were expected to undertake military action on Rome's behalf when local circumstances demanded it. With the growth of the empire these allied states gradually lost their independence and became merely the most privileged class of provincial communities; their number also declined during the Civil Wars, when many revolted or joined the wrong side, and so lost their privileged status. The few that survived into the Principate were known as cīvitātēs foederātae, while the term socii came increasingly to be used indiscriminately for all Rome's free provincial subjects.
Subjects: Classical Studies.