The Battle of Trans-la-Fôret was fought on 1 August 939 between the occupying

Norsemen The Norsemen (or Norse people) were a North Germanic ethnolinguistic group of the Early Middle Ages, during which they spoke the Old Norse language. The language belongs to the North Germanic branch of the Indo-European languages and is the pr ...

and the Bretons, led by a joint army of Alan II, Hugh II of Maine, and

Judicael Berengar Judicael (or Juhel, Judhel, Judhael), thus called in Breton sources, alias Berengar (or Berengarius) his name in Frankish sources, and sometimes known as Judicael Berengar, with both names being used together, was a Count of Rennes in the 10th cen ...

Political landscape

Throughout the early 900's, the states of

Brittany Brittany (; french: link=no, Bretagne ; br, Breizh, or ; Gallo: ''Bertaèyn'' ) is a peninsula, historical country and cultural area in the west of modern France, covering the western part of what was known as Armorica during the period ...

and

West Francia In medieval history, West Francia (Medieval Latin: ) or the Kingdom of the West Franks () refers to the western part of the Frankish Empire established by Charlemagne. It represents the earliest stage of the Kingdom of France, lasting from about ...

were in a state of flux having both being invaded by the Norse: * By 907, a Norse

Hastein Hastein (Old Norse: ''Hásteinn'', also recorded as ''Hastingus'', ''Anstign'', ''Haesten'', ''Hæsten'', ''Hæstenn'' or ''Hæsting'' and alias ''Alsting''Jones, Aled (2003). ''Transactions of the Royal Historical Society: Sixth Series'' Cambridge ...

conquered an area now called

Upper Brittany Upper Brittany (french: Haute-Bretagne; br, Breizh-Uhel; Gallo: ''Haùtt-Bertaèyn'') is the eastern part of Brittany, France, which is predominantly of a Romance culture and is associated with the Gallo language. The name is in counterpoint to ...

, with Nantes renamed to Namsborg as their capital. * In 931, the Norse assembled a army on the Loire river to attack the Franks. The occupied Bretons seized this opportunity and rebelled. The Norse appear to have been taken by surprise but a counterattack ensured Brittany was reconquered. * By 935, the Norse in Brittany became isolated after

William Longsword William Longsword (french: Guillaume Longue-Épée, nrf, Willâome de lon Espee, la, Willermus Longa Spata, on, Vilhjálmr Langaspjót; c. 893 – 17 December 942) was the second ruler of Normandy, from 927 until his assassination in 942.Det ...

of Normandy reconciled with the Franks and exiled Bretons started returning from Anglo-Saxon England. Alan Barbetorte returned to Brittany from Anglo-Saxon England between 936 and 938, and engaged the Norse. A Viking leader Incon was slain and Nantes recaptured in 937. * Receiving support from the Anglo-Saxon King Athelstan, the Bretons spread their rebellion throughout the peninsula and this brought them into direct confrontation with the Norse colonists. Through the course of three years, the campaign against the Norse reached a conclusion at Trans-la-Fôret.

Order of Battle

On August 1, 939, a united Breton army lead by Alan II, a Breton count

of Rennes and elements from a Frankish count Hugh II of

Maine Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and ...

decisively attacked and defeated the Norse stronghold, bringing an end to the occupation. The site of the battlefield is considered to be south of Mont St Michel over the river

Couesnon The Couesnon (; br, Kouenon) is a river running from the ''département'' of Mayenne in north-western France, forming an estuary at Mont Saint-Michel. It is long, and its drainage basin is . Its final stretch forms the border between the histor ...

within a kilometre from Trans-la-Fôret.

Outcome

The Breton victory at

Trans-la-Forêt Trans-la-Forêt () is a commune in the Ille-et-Vilaine department in Brittany in northwestern France. It is the site of the 939 AD Battle of Trans-la-Forêt. Population See also *Communes of the Ille-et-Vilaine department The following is ...

freed

of Viking/Norse occupation and led to the re-establishment of the Breton State, not as a fully independent Kingdom but as a Sovereign Duchy under

Alan II, Duke of Brittany Alan may refer to: People *Alan (surname), an English and Turkish surname *Alan (given name), an English given name **List of people with given name Alan ''Following are people commonly referred to solely by "Alan" or by a homonymous name.'' *Al ...

, due to a new fealty owed to the Franks for helping remove the Norse.Henri-Georges Gaignard. ''Visages de Rance: flâneries à travers les pays malouin et dinannais''. Fernand Lanore, 1983. p 100 The occupation resulted in Brittany becoming more fortified on the seaward side by returning Breton lords. Viking piracy continued to affect a previously vibrant maritime trade between the Bretons and their Welsh cousins, isolating the Bretons. Armorican texts protected by monks for centuries were lost after this period. The Breton capital was moved from Nantes to inland Rennes as it was regarded as more defensible. This would become a point of discord between the two cities.

References

939 930s conflicts Trans-la-Foret Trans-la-Foret 10th century in France Military history of Brittany Viking Age in France {{France-battle-stub