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

Vikings Vikings were seafaring people originally from Scandinavia (present-day Denmark, Norway, and Sweden), who from the late 8th to the late 11th centuries raided, pirated, traded, and settled throughout parts of Europe.Roesdahl, pp. 9� ...

and the

Breton Breton most often refers to: *anything associated with Brittany, and generally **Breton people **Breton language, a Southwestern Brittonic Celtic language of the Indo-European language family, spoken in Brittany ** Breton (horse), a breed **Gale ...

s, led by a joint army of Alan II, Hugh II of Maine, and Judicael Berengar.

Political landscape

Throughout the early 900's, the states of

Brittany Brittany ( ) is a peninsula, historical country and cultural area in the north-west of modern France, covering the western part of what was known as Armorica in Roman Gaul. It became an Kingdom of Brittany, independent kingdom and then a Duch ...

and

West Francia In medieval historiography, West Francia (Medieval Latin: ) or the Kingdom of the West Franks () constitutes the initial stage of the Kingdom of France and extends from the year 843, from the Treaty of Verdun, to 987, the beginning of the Capet ...

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

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 (; ; Gallo: ''Haùtt-Bertaèyn'') is the eastern part of Brittany, France, which is historically associated with the Gallo language. The name is in counterpoint to Lower Brittany, the western part of the ancient province and presen ...

, with

Nantes Nantes (, ; ; or ; ) is a city in the Loire-Atlantique department of France on the Loire, from the Atlantic Ocean, Atlantic coast. The city is the List of communes in France with over 20,000 inhabitants, sixth largest in France, with a pop ...

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

William Longsword William Longsword (, , , ; 893 – 17 December 942) was the second ruler of Normandy, from 927 until his assassination in 942.Detlev Schwennicke, '' Europäische Stammtafeln: Stammtafeln zur Geschichte der Europäischen Staaten'', Neue Folge, ...

of Normandy reconciled with the Franks and exiled Bretons started returning from Anglo-Saxon England. Alan Barbetorte returned to Brittany from

Anglo-Saxon England Anglo-Saxon England or early medieval England covers the period from the end of Roman Empire, Roman imperial rule in Roman Britain, Britain in the 5th century until the Norman Conquest in 1066. Compared to modern England, the territory of the ...

between 936 and 938, and engaged the Vikings. 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 Scandinavian colonists. Through the course of three years, the campaign against the Vikings reached a conclusion at Trans-la-Fôret.

Order of battle

On August 1, 939, a united Breton army led by Alan II, a Breton count Judicael Berengar of

Rennes Rennes (; ; Gallo language, Gallo: ''Resnn''; ) is a city in the east of Brittany in Northwestern France at the confluence of the rivers Ille and Vilaine. Rennes is the prefecture of the Brittany (administrative region), Brittany Regions of F ...

and elements from a Frankish count Hugh II of

Maine Maine ( ) is a U.S. state, state in the New England region of the United States, and the northeasternmost state in the Contiguous United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Provinces and ...

decisively attacked and defeated the Viking 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 (; ) 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 historical duchie ...

within a kilometre from Trans-la-Fôret.

Outcome

The Breton victory at Trans-la-Forêt freed

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

Duchy A duchy, also called a dukedom, is a country, territory, fiefdom, fief, or domain ruled by a duke or duchess, a ruler hierarchically second to the king or Queen regnant, queen in Western European tradition. There once existed an important differe ...

under Alan II, Duke of Brittany, due to a new fealty owed to the Franks for helping remove the Vikings.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

as it was regarded as more defensible. This would become a point of discord between the two cities.

References

{{DEFAULTSORT:Trans-La-Foret 939 939 930s conflicts Battles involving the Vikings Battles involving Francia Battles involving the Duchy of Brittany Military history of Ille-et-Vilaine Viking Age in France