Alamanni (Alemanni), a loose concentration of Germanic communities, under various petty kings, located on former Roman territory west of the Rhine and north of the Danube in the 3rd and later cents. ce. Though not securely attested in our sources until 289, Alamanni of a kind were probably first encountered by Caracalla on the middle Main in 213. ‘Alamanni’—‘All Men’—is Germanic, but its precise derivation and meaning are highly contentious. It may have been the nickname of a small band of warriors, picked up by Rome and applied to the wider grouping for administrative convenience. Ethnically diverse (including former Romans and their descendants), their cultural heartland lay on the Elbe, like Tacitus’ Suebi. But Alamanni were not the product of some great Suebian ‘folk-migration’. Raiders from the Elbe had been probing the Main and its tributaries from the late 2nd cent., with some choosing to settle in the area. By the mid-4th cent. this had created an ‘Elbe-Germanic triangle’, with its base on the Elbe and its apex at the Rhine-knee. Within this triangle there was continued circulation of population. Romans may therefore have applied the term ‘Alamanni’ to Elbe-Germani resident in the top third of this triangle (roughly the old Agri Decumates and northern Raetia): ‘Alamannia’. This labelling was generic, not ethnic: those who left ceased to be Alamanni; newcomers became Alamanni in their turn. Over time, however, and certainly by the 5th cent., the inhabitants of Alamannia recognized themselves as Alamanni and were seen as such by other Germani: an ethnic not a generic. This was part of a general process of *‘ethnogenesis’, by which new Germanic identities were reforged from old in the crucible of the declining empire. Because of their relatively frequent appearance in the sources, Alamanni offer a unique insight into the Romano-Germanic relationship, in particular the conflicting roles of Germani as enemies and allies. Alamanni raided the empire from c.200. They frequently harassed Gaul, in the 3rd cent. penetrating as far as Aquitania; in the mid-4th they won notoriety by their attempt to occupy land west of the Rhine, frustrated by Julian’s victory at *Strasbourg in 357. However, they were mainly feared because of their dangerous proximity to Italy. New epigraphic evidence shows *Iuthungi, later associated with Alamanni, enslaving Italians c.260. Other raids into Italy by Alamanni and Iuthungi in 260, 268/9, and 271 prompted Aurelian’s re-walling of Rome (see wall of aurelian); and emperors took care to develop and maintain the Rhine–Danube–Iller limes, guarding entry into the peninsula. Yet Roman fears, exacerbated by memory of the furor teutonicus of the Cimbric wars, were arguably groundless. Alamanni were scattered, poor, and relatively few. They were also politically divided: never a ‘confederation’, and so never really ‘the’ Alamanni. A highly competitive, violent, warrior-ethos drove them to attack the empire whenever it was vulnerable, above all during civil wars. These attacks were traumatic: archaeological evidence shows that Alamanni tortured captives; and inhabitants of Mainz enslaved by them over Easter 368 must have been profoundly shocked. However, Alamanni posed no strategic threat: they could always be brought to heel. This fundamental inferiority helps explain why Romans permitted Alamanni to move into imperial territory c.262—at a time of huge internal discord when it suited Roman rivals to withdraw tactically from the Rhine–Danube re-entrant without ceding sovereignty of the area. It may also have allowed Roman rulers, such as Julian and Valentinian I, to play up the Alamannic ‘threat’ in order to wage easy, reputation-enhancing wars of ‘retribution’. Alamannic chieftains were incapable of, and probably never wished for or even conceived of, conquest of the empire. After the 3rd cent. they never again threatened Italy; and there are indications that some Alamannic incursions during civil war were instigated by Roman leaders. For most of the 4th cent. they collaborated readily with Rome, in return receiving support for their local status, cash subsidies, exclusive access to manufactured goods, and opportunities for service in the empire. Alamanni, indeed, provided significant numbers of military officers (the most distinguished known being Agilo, senior general of Procopius) and men (in both irregular and regular—limitanei, auxilia palatina—Units). Alamannic settlements also helped block entry into the empire by later generations of raiders from the interior. This is another likely reason why the empire tolerated Alamanni near the frontier, and why it allowed Alamannic construction of great hill-forts near the Rhine (e.g. the Zähringer Burgberg) and along the Swabian Alps. A friendly Alamannia was also useful to Rome as a short-cut from between the Rhine and Danube, and as a source of commodities, including building-stone, iron, salt, slaves, timber, and wheat. As Alamanni did not envisage destruction of the empire, so it was also in Rome’s interests, despite all the sabre-rattling, not to destroy Alamannia. In fact, Alamanni disappeared from Rome’s list of Germanic bogeymen in the later 4th cent., being replaced by Franks. They continued to act as allies, aiding incumbent emperors and usurpers (e.g. Constantine III) alike; irregular units helped hold the Rhine for Aëtius down to the middle of the 5th cent. But, first elbowed aside by Burgundiansc.400 as these pushed down the Main, and then refusing themselves to exploit growing Roman weakness in Gaul after 455, they were eventually absorbed by Clovis’ Franks c.500. Thus, unlike most other large Germanic groupings—Burgundians, Visigoths, Vandals, Ostrogoths, and, most notably, Franks—Alamanni did not create a successor-kingdom. This may be because they had enjoyed too close a symbiosis with the empire, restricting their development and making it difficult for them to cope with a post-Roman world.