Year 851 (DCCCLI) was a common year starting on Thursday of the Julian calendar.
The Duchy of Brittany was a medieval feudal state that existed between approximately 939 and 1547. Its territory covered the northwestern peninsula of Europe, bordered by the Atlantic Ocean to the west, and the English Channel to the north. It was also less definitively bordered by the river Loire to the south, and Normandy, and other French provinces, to the east. The Duchy was established after the expulsion of Viking armies from the region around 939. The Duchy, in the 10th and 11th centuries, was politically unstable, with the dukes holding only limited power outside their own personal lands. The Duchy had mixed relationships with the neighbouring Duchy of Normandy, sometimes allying itself with Normandy, and at other times, such as the Breton–Norman War, entering into open conflict.
Nominoe or Nomenoe was the first Duke of Brittany from 846 to his death. He is the Breton pater patriae and to Breton nationalists he is known as Tad ar Vro.
Erispoe was Duke of Brittany from 851 to his death. After the death of his father Nominoe, he led a successful military campaign against the Franks, culminating in his victory at the Battle of Jengland. He is subsequently referred to as "King of Brittany".
Salomon was count of Rennes and Nantes from 852 and duke of Brittany from 857 until his assassination in 874. In 867, he was granted the counties of Avranches and Coutances, and he used the title king of Brittany intermittently after 868.
Pascweten was the count of Vannes and a claimant to the rule of Brittany. He was a son of Ridoredh of Vannes, a prominent and wealthy aristocrat first associated with the court of Erispoe in the 850s. He owned vast landed estates and salt works in southeastern Brittany and was a patron of Redon Abbey.
Wrhwant, Gurwant, Gurwent or Gurvand was a claimant to the Kingdom of Brittany from 874 until his death in opposition to Pascweten, Count of Vannes.
Alan I, called the Great, was the Count of Vannes and Duke of Brittany from 876 until his death. He was probably also the only King of Brittany to hold that title by a grant of the Emperor.
Judicael was the Duke of Brittany from 876 to his death. He was a son of a daughter of Erispoe and claimed Brittany after the death of the pretenders Wrhwant and Pascweten in mid 876.
Alan II, nicknamed Wrybeard or Twistedbeard, Alan Varvek in Breton, was Count of Vannes, Poher and Nantes, and Duke of Brittany from 938 to his death. He was the grandson of King Alan the Great by Alan's daughter and her husband Mathuedoï I, Count of Poher. He expelled the Vikings/Norsemen from Brittany after an occupation that lasted from 907 to about 939.
Judicael or Judicaël (Welsh:Ithel), also spelled Judhael, was the King of Domnonée, part of Brittany, in the mid-7th century and later revered as a Roman Catholic saint.
Judicael, thus called in Breton sources, alias Berengar 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 century.
The counts of Nantes were originally the Frankish rulers of the Nantais under the Carolingians and eventually a capital city of the Duchy of Brittany. Their county served as a march against the Bretons of the Vannetais. Carolingian rulers would sometimes attack Brittany through the region of the Vannetais, making Nantes a strategic asset. In the mid-ninth century, the county finally fell to the Bretons and the title became a subsidiary title of the Breton rulers. The control of the title by the Breton dukes figured prominently in the history of the duchy. The County of Nantes was given to Hoel, a disinherited son of a duke. He lost the countship due to a popular uprising. That uprising presented an opportunity for King Henry II of England to attack the Breton duke. In the treaty ending their conflicts, the Breton duke awarded the county to Henry II.
Gwened, Bro-Gwened or Vannetais is a historic realm and county of Brittany in France. It is considered part of Lower Brittany.
Lambert II was the Frankish Count of Nantes and Prefect of the Breton March between 843 and 851. Lambert ruled the county in opposition to Amaury, the puppet count installed by Charles the Bald, King of West Francia. At his death, the county was effectively in Breton control. Lambert was the son of Lambert I and his wife Itta.
The Battle of Jengland took place on 22 August 851, between the Frankish army of Charles the Bald and the Breton army of Erispoe, Duke of Brittany. The Bretons were victorious, leading to the signing of the Treaty of Angers in September 851 and the recognition of Erispoe as the legitimate ruler of the Bretons under Charles the Bald.
The Battle of Blain, also called the Battle of Messac, was fought on 24 May 843 by the forces of Lambert II of Nantes and Erispoe, prince of Brittany, against Renaud, Frankish Count of Nantes. It arose from Breton resistance to Frankish power within Brittany and disputes over control of the County of Nantes. The defeat of the Franks led to a period of Breton expansionism.
The Kingdom of Brittany was a short-lived vassal-state of the Frankish Empire that emerged during the Norse invasions. Its history begins in 851 with Erispoe's claim to kingship. In 856, Erispoe was murdered and succeeded by his cousin Salomon.
Waroch I was an early ruler of the Bro Wened (Vannetais) in southern Brittany. It is unclear whether he or his grandson Waroch II is the namesake of the region.
