History Files

European Kingdoms

Celts of Armorica


Leon (Armorican Romano-Britons)

The north-western corner of today's France was known during the Roman period as Armorica. The tribe of the Veneti had been the most powerful of Armorica's tribes, and that name gradually changed during the Roman occupation to Vannetais. This was how Armorica was initially known to the Britons who began migrating there in the fourth century AD, during a period in which British town life appears to have declined.

The low-key migration from Britain into Armorica seems to have picked up noticeably in the mid-fourth century, but it became a flood in the unsettled fifth century. Traditional certainly maintains that the British colony in Armorica was founded before the expedition of Constantine III in 407. People arrived mainly from the south-west of Britain, from Dumnonia and Cornubia, and each group retained its ethnic name (ergo the people in each region knew exactly what they were ethnically or tribally, regardless of who was king over them).

FeatureThis new colony of Britons formed in a region which was beginning to drift out of firm Roman control. The colony's traditional first king, Conan Meriadog, ruled Armorica as the kingdom of Vannetais, maintaining the local Gaulish tribal name. The area was permanently 'freed' of Roman control by Magnus Maximus as the first stage of his invasion of Gaul in 383 (see feature link). Conan was placed in command, with a probable capital in Vannes. The usual Celtic practice of dividing territory between sons soon created the smaller principalities out of Vannetais during the course of the fifth and sixth centuries whilst other Britons also popped over from the mainland to found their own principalities.

FeatureSituated to the far west of Armorica, Leon (or Léon in modern French) was an exceptionally short-lived early principality, one which seemingly lasted no more than two generations in the sixth century before being absorbed into greater Brittany. Its name suggests that it may have been colonised by Britons from Lyonesse. Its location in relation to the other Armorican principalities also supports this. Four (self-identifying) sub-ethnic groups seem to have moved to Armorica to settle in a geographical order which matched that of their homelands in Britain - from west to east these were Leon, Cornouaille, Domnonia, and Rennes. However, the existence of Lyonesse is pretty debatable and perhaps nothing more than hypothetical. Early romancers may have been referring to Leon itself when they mentioned this small principality.

An alternative name origin is the fact that medieval sources sometimes name the region pagus Leonensis, which Koch states as being a variation of pagus Legionensis, making it the 'country of the Legion'. The main stronghold in the region, Gesocribate, developed into the port of Brest and this could be referred to in its early days as urbs Legionum - 'city of the Legion'. This points to a foundation as a Roman or early post-Roman military zone, one which housed a legion or its later equivalent. Interestingly, the possibility of its being post-Roman means that the legion in question could have been one of those under the command of Magnus Maximus or his near successor, Constantine III. Also valid is the point that Lyonesse could share this name origin if a supposition is allowed that it could have provided a home to retired legionnaires.

Curiously, in terms of the first naming theory, the diminutive territory of Lyonesse (probably the Scilly Isles) was seemingly re-absorbed into Corniu in the mid-sixth century. This seems to be around the same time that the first of Leon's short list of princes appeared, when the territory retained very strong links with south-west Britain. Speaking very theoretically, perhaps the heir to Lyonesse was given British territory in Brittany in compensation for the loss of Lyonesse itself. After the Arthurian period (and perhaps also during it) coastal water levels were rising substantially, partially inundating the greater Scilly Isles and turning a single landmass into a chain of small islands. Overall it remained part of Dumnonia and ended up being unconquered but subjugated along with the remains of that kingdom in the form of Cornwall. Irish raids may also have formed part of the problem, forcing the majority of Lyonesse's population to relocate to Leon.

Roman Canterbury

(Information by Peter Kessler, with additional information by Geoffrey Tobin and Edward Dawson, from Brittany: Many Kingdoms or One?, Jean-Michel Pognat, from Province and Empire: Brittany and the Carolingians, Julia M H Smith, part of The Cambridge Studies in Medieval Life and Thought series (1992), from The Ethnology of Germany Part 3: The Migration of the Saxons, Henry H Howorth (Journal of the Anthropological Institute of Great Britain and Ireland, Vol 7, 1878), from The History of the Franks, Volume II, Gregory of Tours (O M Dalton, Trans, 1967), from The History of Normandy and of England, Francis Palgrave (1864), and from Celtic Culture: An Historical Encyclopaedia, Vol 1 A-Celti, John T Koch (Ed).)


The death of the heirless Pawl of Penychen sees his minor kingdom pass to his nephew, Catocus. If the medieval 'invention' of Pawl is one and the same as the earlier-named Perphirius then he is in fact the father of St Paul Aurelian who is to find success as the first bishop of Leon.

Map of Armorica
Vannetais was created during the late fourth century AD, enjoying a peak of expansion and power up until 491 (click or tap on map to view full sized)


The diminutive territory of Lyonesse may be re-absorbed into Corniu at a time in which the peninsula receives extremely little mention in history. Dumnonia firmly controls the entire south-west of Britain. Curiously, this seems to be around the same time that the first of a short list of kings appear in Leon in Brittany, which of course retains very strong links at this time with south-west Britain.

fl c.550


Son of Rivold/Rhiwod, son of Budig II of Vannetais.

fl c.570




Chilperic, king of the Franks, sends an army to fight Waroch of Bro Erech along the Vilaine. The Frankish army consists of units from Anjou, Bayeux, Maine, Poitou, and Touraine. The Baiocassenses, the 'men from Bayeux', are Saxons. They in particular are routed by the Bretons over the course of three days of fighting.

Waroch is still forced to submit in the end, and pays homage by sending his son as a hostage and agreeing to pay an annual tribute. He subsequently breaks the latter promise, but Chilperic's dominion over the Bretons (or at least their eastern borders) is relatively secure as evidenced by Venantius Fortunatus' celebration of it in a poem.


The principality comes to an end with Ausoch, before the region's capital of Saint-Pol-de-Léon has even been formed. However, the early princes of Leon may have been occupying the fortified Gallo-Roman town of Gesocribate, formerly a stronghold of the Osismii tribe and later to develop as the port of Brest (urbs Legionum, city of the Legion).

Brest Castle, Gesocribate, urbs Legionum
The lower section of the medieval Brest Castle is Roman, originally laid around AD 290 and still visible along about half of the modern walls - it is this fortress which provided the original urbs Legionum and the British stronghold of Gesocribate

An an unknown point in Brittany's medieval history, Leon is revived as a viscounty which is nominally under the authority of the king or duke of Brittany. This is seemingly from the mid-eleventh century when the earliest-known of its viscounts flourishes, appointed by the dukes of Cornouaille. In reality, though, it is largely autonomous until the mid-twelfth century invasion of France by Henry II of England.

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