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.
Joan of Penthièvre reigned as Duchess of Brittany together with her husband, Charles of Blois, between 1341 and 1364. Her ducal claims were contested by the House of Montfort, which prevailed only after an extensive civil war, the War of the Breton Succession. After the war, Joan remained titular Duchess of Brittany to her death. She was Countess of Penthièvre in her own right throughout her life.
The War of the Breton Succession was a conflict between the Counts of Blois and the Montforts of Brittany for control of the Sovereign Duchy of Brittany, then a fief of the Kingdom of France. It was fought between 1341 and 12 April 1365. It is also known as the War of the Two Jeannes due to the involvement of two rival duchesses of that name.
John of Montfort, sometimes known as John IV of Brittany, and 6th Earl of Richmond from 1341 to his death. He was the son of Arthur II, Duke of Brittany and his second wife, Yolande de Dreux. He contested the inheritance of the Duchy of Brittany by his niece, Joan of Penthièvre, which led to the War of the Breton Succession, which in turn evolved into being part of the Hundred Years' War between England and France. John's patron in his quest was King Edward III of England. He died in 1345, 19 years before the end of the war, and the victory of his son John IV over Joan of Penthièvre and her husband, Charles of Blois.
Charles of Blois-Châtillon, nicknamed "the Saint", was the legalist Duke of Brittany from 1341 until his death, via his marriage to Joan, Duchess of Brittany and Countess of Penthièvre, holding the title against the claims of John of Montfort. The cause of his possible canonization was the subject of a good deal of political maneuvering on the part of his cousin, Charles V of France, who endorsed it, and his rival, Montfort, who opposed it. The cause fell dormant after Pope Gregory XI left Avignon in 1376, but was revived in 1894. Charles of Blois was beatified in 1904.
John IV the Conqueror KG, was Duke of Brittany and Count of Montfort from 1345 until his death and 7th Earl of Richmond from 1372 until his death.
John I was the Duke of Lorraine from 1346 to his death. As an infant of six months, he succeeded his father, Rudolph, who was killed in the Battle of Crécy. His mother was Marie of Blois.
Sir John Chandos, Viscount of Saint-Sauveur in the Cotentin, Constable of Aquitaine, Seneschal of Poitou, was a medieval English knight who hailed from Radbourne Hall, Derbyshire. Chandos was a close friend of Edward the Black Prince and a founding member and 19th Knight of the Order of the Garter in 1348. Chandos was a gentleman by birth, but unlike most commanders of the day he held no inherited title of nobility.
Bertrand du Guesclin, nicknamed "The Eagle of Brittany" or "The Black Dog of Brocéliande", was a Breton knight and an important military commander on the French side during the Hundred Years' War. From 1370 to his death, he was Constable of France for King Charles V. Well known for his Fabian strategy, he took part in seven pitched battles and won the five in which he held command.
Sir Robert Knolles or Knollys was an English knight of the Hundred Years' War, who, operating with the tacit support of the crown, succeeded in taking the only two major French cities, other than Calais and Poitiers, to fall to Edward III. His methods, however, earned him infamy as a freebooter and a ravager: the ruined gables of burned buildings came to be known as "Knollys' mitres".
Olivier V de Clisson, nicknamed "The Butcher", was a Breton soldier, the son of Olivier IV de Clisson. His father had been put to death by the French in 1343 on the suspicion of having willingly given up the city of Vannes to the English.
The Battle of Cocherel was fought on 16 May 1364 between the forces of Charles V of France and the forces of Charles II of Navarre, over the succession to the dukedom of Burgundy. The result was a French victory.
This is a timeline of the Hundred Years' War between England and France from 1337 to 1453 as well as some of the events leading up to the war.
Sir Hugh Calveley was an English knight and commander, who took part in the Hundred Years' War, gaining fame during the War of the Breton Succession and the Castilian Civil War. He held various military posts in Brittany and Normandy. He should not be confused with his nephew, also Sir Hugh Calveley, who died in June 1393 and was Member of Parliament for Rutland.
Jean, or Jehan de Beaumanoir, marshal of Brittany for Charles of Blois, and captain of Josselin, is remembered for his share in the famous Combat of the Thirty during the War of Breton Succession (1341–1364) between the warring parties of competing claimants for the Dukedom.
The Caroline War was the second phase of the Hundred Years' War between France and England, following the Edwardian War. It was so-named after Charles V of France, who resumed the war nine years after the Treaty of Brétigny. In this part of the conflict, the Crown of Castile emerges as a supporter of France. The Kingdom of France dominated this phase of the war.
The Battle of Champtoceaux, often called the Battle of l'Humeau, was the opening action of the 23-year-long War of the Breton Succession, a dynastic conflict in the Sovereign Duchy of Brittany which became inevitably embroiled in the Hundred Years War between England and France. This battle should have decided the war at a stroke, as John of Montfort, the leader of one faction, was made prisoner. However his wife, Joanna of Flanders, and young son John escaped imprisonment. Their escape and continued support from his ally, England, allowed continued resistance to flourish and eventually turn the tide.
The first treaty of Guérande, signed on 12 April 1365, ended the Breton War of Succession.
Following the defeat of Mauron during the Breton War of Succession, the Franco-Bretons, led by Bertrand Du Guesclin, took their revenge at the Battle of Montmuran on April 10, 1354.
Guillaume Boitel, was a knight and the faithful companion of the French knight Bertrand Du Guesclin. He was originally sent by king Charles V of France to assist Du Guesclin during the Anglo-French war in Normandy and the Breton War of Succession between Charles de Blois and Jean de Montfort (1363-1364).
House of Montfort, Brittany 
Kingdom of England 
Kingdom of France 
John de Montfort 
John Chandos 
Charles of Blois † 
Bertrand du Guesclin (POW)
