History Files


European Kingdoms

Celtic Tribes




MapOsi / Onsi (Suevi)

FeatureIn general terms, the Romans coined the name 'Gaul' to describe the Celtic tribes of what is now central, northern and eastern France. The Gauls were divided from the Belgae to the north by the Marne and the Seine, and from the Aquitani to the south by the River Garonne. They also extended eastwards, into the region that was becoming known as Germania. The Celts had ruled much of this in their heyday, but by the middle of the first century BC they were fragmented, and were either in the process of being expelled by the increasingly powerful Germanic tribes who were migrating southwards from Scandinavia and the Baltic coast, or they were being defeated and integrated into Germanic or other tribes. The Osi were located in the Galicia region which today roughly forms the meeting point between eastern Slovakia, southern Poland and western Ukraine. They were neighboured by the Manimi, Harii, Cotini, and the Germanic Buri, as well as by the mighty Boii to the west.

The Osi (or Onsi) tribal name is pretty distinctive, and unusual. Their very simple name, without any plural suffixes, suggests they may have been located at a river mouth. However their known first century BC location was precisely the opposite, at the headwaters of several prominent rivers. While their name seems to mean 'river mouth' in Old Norse, in Old English it suggests 'beginning, origin (neut.), bank (masc. n-stem)'. As it is related to the Sanskrit word for 'mouth' it is strongly suspected that the name was 'source [of a river]', keeping in line with the Old English meaning rather than the Norse meaning. So the tribe were probably named after a settlement at the source of a river.

The Osi formed one of the minor constituent tribes of the vast Suevi confederation. This was a confederation of Germanic peoples that came into existence by the first century AD, and perhaps earlier. Their number included the tribes of the Alemanni, Angles, Hermunduri, Langobards, Marcomanni, Quadi, Semnones, and Warini, and perhaps also the Heruli too. None of these tribes were what could be considered 'front line' tribes, living along the border with the Roman empire. Instead they were arrayed behind a large number of other tribes which were better known and better attested by Roman writers. The Suebic tribes remained a little more obscure, at least until they came into direct contact with the empire, and many of the more minor tribes that made up the confederation were almost entirely unchronicled.

(Additional information by Edward Dawson, and from The Oxford History of England: Roman Britain, Peter Salway, from the Complete Works of Tacitus, Alfred John Church, William Jackson Brodribb, Lisa Cerrato, 1942, from The Celtic Encyclopaedia, Harry Mountain, and from The Osi of Tacitus - Germanic or Illyrian?, Joshua Whatmough.)

6th century BC

The Osi belong to the Hallstatt culture of Celts, along with the Bebryces, Boii, Cotini, Harii, Helisii, Helveconae, Manimi, and at least some elements of the later Lugii. They are to be found around the central German lands, and in Bohemia, Moravia, Slovakia, and the edges of Poland and Ukraine. Around this time a large-scale expansion begins that sees many Hallstatt Celts migrate outwards, towards northern Italy, Gaul, or Iberia. Many others remain, and they control the region until pressure from newly-arriving Germanic tribes begins to erode their hold in the second and first centuries BC.

The landscape of Bohemia (extending into Slovakia) is and was defined by wooded mountainsides and extensive farming land - a green and fertile area at the centre of Europe and of the Hallstatt culture

The Osi are known to migrate from the modern German-Czech border into the Silesia area of Poland around this time where they become iron miners in this deposit-rich environment. By the first century BC they largely inhabit the region of Galicia. Their territory in the foothills of the Carpathians contains the headwaters of the Oder, Vistula, and a tributary of the Danube.

c.100 BC

During an unknown point in the second century BC, a division of the Osi migrate south to enter Pannonia, on the southern bank of the Danube. Here they become lowland farmers, surrounded by the Illyrian Antari tribe who seem not to oppose their arrival (possibly this is due to the dominance of the Celtic Taurisci confederation). Some scholars have labelled this group as the Osones, perhaps to avoid confusion with their northern kin (confusion not helped by Tacitus who mentions both groups by the same name), and perhaps by a reluctance to accept a common origin for both groups. The reason for the migration could be the increasing advance of German tribes from the north, as shown by events at the end of the century.

For the Osi, the Germanic advance means that by around 100 BC the remaining Osi in Galicia are cut off from the Celtic world by the infringement of the Quadi. They have to pay tribute to the militarily dominant Germans and a tribe of Sarmatians. Unusually, though, they are not absorbed by the Germans and manage to retain their language.

AD 98

Writing in AD 98, Tacitus mentions the Osi twice, once in their original homeland in Galicia and once in Pannonia. He is of the opinion that the Pannonian group are speakers of the Pannonian language, although perhaps only in order to differentiate them from Germans. Either their Celtic language is being ignored, or he has not been properly informed of it, or they have become naturalised with their Pannonian neighbours.

177 - 179

At the end of a renewed campaign by Marcus Aurelius against the Marcomanni, the emperor has 40,000 Romans posted on Marcomannic and Quadian territory and has the Cotini and Osi resettled from Slovakia to southern Pannonia. The newly free territories are mainly settled by the Quadi.

Roman defensive tower
Emperors Hadrian and Antoninus Pius had concentrated on defining the Roman empire's borders, defending the territory they had. That would have included building watch towers along the limes in the Danube region which the Marcomanni managed to break through


By this time, the Suevi have formed a wide-ranging confederation of tribes that are all known individually but which are counted as being Suevi. The vast number of tribes included in the confederation include the Aestii, Angles, Aviones, Buri, Cotini, Eudoses, Gutones, Hermunduri (who have virtually ceased to exist as a recognisable independent people), Langobards, Lugii (a name applied to several tribes: the Harii, Helisii, Helveconae, Manimi, and Naharvali), Marcomanni, Marsigni, Naristi, Nuitones, Osi, Quadi, Reudigni, Semnones, Sitones, Suardones, Suiones (Swedes), and the Warini.

After this period the Osi disappear into the Suevi collective in Galicia, probably to form part of the region's modern population. The Pannonian branch also disappears, possibly as part of the Noricum.