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European Kingdoms

Celtic Tribes




Index of Celtic TribesMapOsismii (Gauls)

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. By the middle of the first century BC, the Osismii were located in the far north-west of Gaul, on the Brittany peninsula. They were neighboured to the south-east by the Veneti, to the east by the Redones, to the north by the Cariosvelites, and across the English Channel by the Dumnonii and Durotriges.

The tribe were called the Ostinioi in fourth century BC Greek (by Pytheas). This looks remarkably similar to the proposed proto-Celtic *ouxselo, meaning 'high', ancestral to the modern Welsh 'uchel', meaning 'high, lofty, prominent', and its extended meaning, 'a nobleman'. In the modern Welsh there are multiple endings and beginning mutations: 'uchel' [uched, cyfuwch, cuwch; uwch; uchaf]. Uchaf is the superlative case: 'uchaf' (adj.), meaning 'highest, uppermost'. Note the last one: 'uchaf'. That 'f' is actually pronounced 'v' and was originally an 'm'. Add that 'm' to the proto-Celtic to replace the 'l' and the result is 'ouxsem', not too far from 'ostim' and easily misheard as it. It seems that Pytheas came the closest to getting it right, and the tribe were most likely the Ostimii, 'the highest' or 'the loftiest'.

They were first mentioned by the aforementioned Greek navigator, Pytheas. Writing in the fourth century BC, he located them on the coast near a 'Cape Kabaļon' which is probably either pointe de Penmarc'h or pointe du Raz, both of which are on the lower western coast of Brittany. Their territory roughly matches the modern Breton region of Finistere, plus perhaps the western part of the Cōtes-d'Armor. They had settlements at Vorgium Osismiorum, (identified as modern Carhaix, and the capital of the Breton principality of Poher in the sixth century AD), and Vorganium, and an oppidum at Yaudet. Additionally there was also the fortified Gallo-Roman town of Gesocribate (modern Brest) which may have appeared after their conquest and which may also have provided a stronghold for the later principality of Leon in this area. Along with their neighbours, the tribe provided the Romans with stiff resistance, and they suffered for it by being given the highly unfavourable status of civitates stipendiariae, which implies that they were forced to pay higher taxes and provide soldiers for the Roman army.

(Information co-authored by Edward Dawson, and additional information from The La Tene Celtic Belgae Tribes in England: Y-Chromosome Haplogroup R-U152 - Hypothesis C, David K Faux, from Celtic Culture: An Historical Encyclopaedia, Vol 1 A-Celti, John T Koch (Ed), and from External Link: The Works of Julius Caesar: Gallic Wars. Other major sources listed in the 'Barbarian Europe' section of the Sources page.)

c.325 BC

FeaturePytheas of Massalia undertakes a voyage of exploration to north-western Europe, becoming the first scholar to note details about the Celtic and Germanic tribes there. One of the tribes he records is the Ostinioi - almost certainly the Osismii - who occupy Cape Kabaļon, which is probably pointe de Penmarc'h or pointe du Raz in western Brittany. This means that the tribe has already settled the region by the mid-fourth century, probably alongside their neighbours of later years, the Veneti, Cariosvelites, and Redones.

Ptolemy's map of Britain
The details recorded by Pytheas were interpreted by Ptolemy in the second century AD, and this 1490 Italian reconstruction of the section covering the British Isles and northern Gaul shows Ptolemy's characteristically lopsided Scotland at the top

57 BC

The Belgae enter into a confederacy against the Romans in fear of Rome's eventual domination over them. They are also spurred on by Gauls who are unwilling to see Germanic tribes remaining on Gaulish territory and are unhappy about Roman troops wintering in Gaul. The Senones are asked by Julius Caesar to gain intelligence on the intentions of the Belgae, and they report that an army is being collected. Caesar marches ahead of expectations and, in a single campaigning season, the Belgic tribes are defeated or surrender to Rome. According to Caesar, the Aulerci, Cariosvelites, Osismii, Redones, Sesuvii, Venelli, and Veneti, all of whom are located along the Atlantic coast, are subdued by the legion of Publius Licinius Crassus. With this action, northern Gaul has been brought under Roman domination.

56 BC

Following his successful campaign against the Belgae in the previous year, Caesar sets out for Illyricum. Once he has left, war flares up again, triggered by Publius Licinius Crassus and the Seventh Legion in the territory of the Andes. With supplies of corn running low, he sends scavenging parties into the territories of the Cariosvelites, Esubii, and the highly influential Veneti. The latter revolt against this infringement of their lands and possessions, and the neighbouring tribes rapidly follow their lead, including the Ambiliati, Diablintes, Lexovii, Menapii, Morini, Namniti, Nannetes, and Osismii. The Veneti also send for auxiliaries from their cousins in Britain. Julius Caesar rushes back to northern Gaul, to a fleet that is being prepared for him by the (Roman-led) Pictones and Santones on the River Loire. The Veneti and their allies fortify their towns, stock them with corn harvests from the surrounding countryside, and gather together as many ships as possible. Knowing that the overland passes are cut off by estuaries and that a seaward approach is highly difficult for their opponents, they plan to fight the Romans using their powerful navy in the shallows of the Loire.

Before engaging the Veneti, Caesar sends troops to the Remi, Treveri, and other Belgae to encourage them to keep to their allegiance with Rome and to hold the Rhine against possible incursions by Germans who may be planning to join the Veneti. This works, with even the previously militant Bellovaci remaining subdued during this revolt. Crassus is sent to Aquitania and Quintus Titurius Sabinus to the Cariosvelites, Lexovii and Venelli, to prevent them sending reinforcements to the Veneti. Sabinus finds that Viridovix of the Venelli has joined the revolt, along with the Aulerci and Sexovii, who have killed their magistrates for wanting to remain neutral. Sabinus remains in his well-fortified camp, resisting the taunts of the Venelli and their allies until they venture too far forwards, allowing a Roman sally across the defensive ditch and into the fleeing Celtic ranks. This area of the revolt is instantly extinguished.

Romans attack a Veneti vessel
Roman auxiliaries in the form of the Aeduii attack a Veneti vessel in Morbihan Bay on the French Atlantic coast during the campaign of 56 BC

The campaign by Caesar against the Veneti is protracted and takes place both on land and sea. Veneti strongholds, when threatened, are evacuated by sea and the Romans have to begin again. Eventually the Veneti fleet is cornered and defeated in Quiberon Bay by Legate Decimus Junius Brutus Albinus. The Veneti strongholds are stormed and much of the Veneti population is either captured and enslaved or butchered. The confederation is destroyed and Roman rule is firmly stamped upon the region.

52 BC

While Caesar is tied down in Rome, the Gauls begin their revolt, resolving to die in freedom rather than be suppressed by the invaders. The Carnutes take the lead under Cotuatus and Conetodunus when they kill the Roman traders who have settled in Genabum. News of the event reaches the Arverni that morning, and Vercingetorix summons his people to arms. His cavalry subsequently routed in battle, he withdraws in good order to Alesia, a major fort belonging to the Mandubii. The remaining cavalry are dispatched back to their tribes to bring reinforcements. Caesar begins a siege of Alesia, aiming on starving out the inhabitants.

Four relief forces amounting to a considerable number of men and horses are assembled in the territory of the Aeduii by the council of the Gaulish nobility. Among those demanded from the tribes of Gaul are six thousand men combined from the tribes of Armorica (including the Ambibari, Caleti, Cariosvelites, Lemovices, Osismii, Redones, Venelli, and Veneti). Together they attempt to relieve Vercingetorix at the siege of Alesia, but the combined relief force is soundly repulsed by Julius Caesar. Seeing that all is lost, Vercingetorix surrenders to Caesar. The garrison is taken prisoner, as are the survivors from the relief army. They are either sold into slavery or given as booty to Caesar's legionaries, apart from the Aeduii and Arverni warriors who are released and pardoned in order to secure the allegiance of these important and powerful tribes.

The site of Alesia
The site of Alesia, a major fort belonging to the Mandubii tribe of Celts, was the scene of the final desperate stand-off between Rome and the Gauls in 52 BC

With this action, all of Gaul has been brought under Roman domination, and the history of its population of Celts is tied to that of the empire. The Osismii suffer for their consistent refusal to be subdued by being given the highly unfavourable status of civitates stipendiariae, which implies that they are forced to pay higher taxes and provide soldiers for the Roman army.