Foederati were peoples or cities bound to Rome by a treaty, called a foedus. In the later empire the word mostly meant barbarian groups, such as the Goths, who were settled on Roman land in return for military service.
Key takeaways
- The word comes from the Latin foedus, a treaty, and in the Republic it described Rome's Italian allies.
- In the late empire foederati were barbarian groups given land and benefits in exchange for fighting for Rome.
- The Goths were accepted as foederati after crossing the Danube in 376, and the empire relied on such troops more after the defeat at Adrianople in 378.
- On our map, the empire's frontier provinces are shown as ordinary provinces until they are marked lost, with no separate layer for allies.
How the foederati worked
The Latin word foedus means a treaty, and foederati were the peoples and cities bound to Rome by one [1]. During the Republic the term described Rome's allies in Italy, who were known as socii. Under the empire it was used for foreign states, client kingdoms and barbarian tribes that received benefits from Rome in exchange for military help [1].
The system changed in the later empire. In 376, a large group of Goths fleeing the Huns asked to cross the Danube, and the empire let them settle on the southern bank and accepted them as foederati [1]. They were mistreated, rose in revolt, and defeated the Romans at the Battle of Adrianople in 378. The loss of so many soldiers forced the empire to depend much more on foederati from then on [1].
The bargain was simple: benefits from Rome in return for fighters when Rome asked. It could work well, but the loyalty of the tribes and their chieftains was never reliable [1]. In 395, the Visigoths under Alaric rebelled [1]. In the Western empire, groups including the Visigoths, Burgundians and Suebi were settled inside imperial territory as foederati [2].
The end of the West came through the same system. In 476 Odoacer, a commander of foederati, deposed Romulus Augustulus and sent the imperial insignia to Constantinople [1]. The East kept using foederati too, and they were still in its army in the sixth century [1].
An example from our data
The map does not draw foederati, treaty lands or barbarian kingdoms, so it cannot show who was settled where. What it can show is the frontier they crossed or lived behind. The southern bank of the lower Danube is where our map draws Moesia Inferior, with its capital at Novae and today's Bulgaria and Romania inside it, and it sits in the Eastern half. Modern Bulgaria first appears on the map at 133 BC and last at AD 1180, with 102 Roman places from the Pleiades gazetteer. These are key dates on the slider, not the real years of conquest or loss.
Now compare the whole empire at two dates. At AD 395 it measures 4.72 million km² (the year 395 page). At AD 476, once the West has gone, it measures 1.94 million km² (the year 476 page). The Western provinces that disappear in between include land that foederati and other peoples came to hold, though our map marks only the date each province was lost.
The thing people get wrong
Foederati are often described as "the barbarians" or as "the enemy inside the walls". In fact the word meant allies, and many foederati fought for Rome loyally. They defended frontiers, took part in campaigns and served under commanders such as Belisarius and Narses in the East [1]. It also was not only a late, barbarian arrangement: Rome had allied peoples bound by treaty from the Republic onward [1]. What changed was how much the empire depended on them.
Foederati vs client kingdom
| Foederati | Client kingdom | |
|---|---|---|
| Main idea | A people bound by a treaty to give military help | A kingdom ruled by its own king under Rome's protection |
| Where they lived | Often settled inside the empire | Usually on or beyond the frontier |
| Typical period | Mostly the later empire | Mostly the Republic and early empire |
Frequently asked questions
What does foederati mean?
It is the plural of the Latin foederatus, meaning an ally bound by a treaty (a foedus). In the later empire it meant barbarian allies who fought for Rome.
Were foederati part of the Roman army?
They fought for Rome and sometimes alongside the legions, but they were allied peoples bound by treaty, not men recruited one by one into the regular army.
Did foederati cause the fall of the Western empire?
They were part of the story. Foederati helped to defend the West, but their loyalty was not always reliable, and in 476 their commander Odoacer deposed the last Western emperor.
Sources
- Foederati, Wikipedia.
- Western Roman Empire, Wikipedia.
- Every figure from our own map is worked out from the datasets on the data sources page (checked against Ancient World Mapping Center outlines and Pleiades).