The siege of Orléans marked a turning point of the Hundred Years' War between France and England. The siege took place at the pinnacle of English power during the later stages of the war, but was repulsed by French forces inspired by the arrival of Joan of Arc. The French would then regain the initiative in the conflict and began to recapture territories previously occupied by the English.
The siege of Rouen was a major event in the Hundred Years' War, in which English forces loyal to Henry V captured Rouen, the capital of Normandy, from the Norman French.
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.
Joanna of Flanders was Duchess of Brittany by her marriage to John of Montfort. Much of her life was taken up in defence of the rights of her husband and, later, son to the dukedom, which was challenged by the House of Blois during the War of the Breton Succession. Known for her fiery personality, Joanna led the Montfortist cause after her husband had been captured, and began the fight-back, showing considerable skill as a military leader.
The siege of Calais occurred at the conclusion of the Crécy campaign, when an English army under the command of King Edward III of England successfully besieged the French town of Calais during the Edwardian phase of the Hundred Years' War.
The Battle of Saint-Pol-de-Léon was a minor action during the Breton War of Succession and thus part of the larger Hundred Years War. The battle was fought in June 1346 and marked a minor turning point in the fortunes of the Montfortists and their English allies in Brittany following several setbacks including the imprisonment and subsequent death of their leader, John of Montfort.
The Battle of La Roche-Derrien was one of the battles of the Breton War of Succession; it was fought on 20 June 1347 during the night between Anglo-Breton and Franco-Breton forces. Approximately 4,000–5,000 French, Breton and Genoese mercenaries laid siege to the town of La Roche-Derrien in the hope of luring Sir Thomas Dagworth, the commander of the only standing English field army in Brittany at the time, into an open pitched battle.
The Battle of Morlaix was fought in Morlaix on 30 September 1342 between the Anglo-Breton and Franco-Breton forces in Brittany. The Anglo-Breton under English command besieged the town, but a Franco-Breton relief force arrived. The English constructed a strong defensive position. After repeated attacks, the French forced the English to retreat into the woods, and the French force then withdrew.
The Battle of Caen was an assault conducted on 26 July 1346 by forces from the Kingdom of England, led by King Edward III, on the French-held town of Caen and Normandy as a part of the Hundred Years' War.
The Battle of Saint-Omer, fought on 26 July 1340, was a major engagement in the early stages of the Hundred Years' War, during Edward III's 1340 summer campaign against France launched from Flanders. The campaign was initiated in the aftermath of the English naval victory at the Battle of Sluys but was far less successful than Edward had hoped. At Saint-Omer, the heavily-outnumbered French men-at-arms, tasked with defending the city and awaiting reinforcements, unexpectedly defeated the Anglo-Flemish forces on their own. The allies suffered heavy losses and the French captured their camp intact, taking many warhorses, draft animals and carts, all the tents, huge quantities of supplies and most of the Flemish standards. Edward's campaign of 1340 had begun badly. On the bright side, the loss of several thousand men was bearable, as the survivors, which included most of the precious English longbowmen, eventually rejoined him at Tournai. The defeat had serious strategic consequences. It exposed southern Flanders to the wrath of Philip VI and enabled the French to concentrate their forces against the main army of the coalition in the siege of Tournai.
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 Battle of Calais took place in 1350 when an English force defeated an unsuspecting French army which was attempting to take the city. Despite a truce being in effect the French commander Geoffrey de Charny had planned to take the city by subterfuge, and bribed Amerigo of Pavia, an Italian officer of the city garrison, to open a gate for them. The English king, Edward III, became aware of the plot and personally led his household knights and the Calais garrison in a surprise counter-attack. The French were routed by this smaller force, with significant losses and all their leaders captured or killed.
The sieges of Vannes of 1342 were a series of four sieges of the town of Vannes that occurred throughout 1342. Two rival claimants to the Duchy of Brittany, John of Montfort and Charles of Blois, competed for Vannes throughout this civil war from 1341 to 1365. The successive sieges ruined Vannes and its surrounding countryside. Vannes was eventually sold off in a truce between England and France, signed in January 1343 in Malestroit. Saved by an appeal of Pope Clement VI, Vannes remained in the hands of its own rulers, but ultimately resided under English control from September 1343 till the end of the war in 1365.
Lancaster's chevauchée of 1356 in Normandy was an English offensive directed by Henry, Duke of Lancaster, in northern France during 1356, as a part of the Hundred Years' War. The offensive took the form of a large mounted raid – a chevauchée – and lasted from 22 June to 13 July. During its final week the English were pursued by a much larger French army under King John II that failed to force them to battle.
The sieges of Berwick were the Scottish capture of the town of Berwick-upon-Tweed on 6 November 1355 and their subsequent unsuccessful siege of Berwick Castle, and the English siege and recapture of the town in January 1356. In 1355 the Second War of Scottish Independence had been underway for over 22 years. After a period of quiescence the Scots, encouraged by the French who were fighting the English in the Hundred Years' War, assembled an army on the border. In September a truce was agreed and much of the English army left the border area to join King Edward III's campaign in France.
The siege of Guînes took place from May to July 1352 when a French army under Geoffrey de Charny unsuccessfully attempted to recapture the French castle at Guînes which had been seized by the English the previous January. The siege was part of the Hundred Years' War and took place during the uneasy and ill-kept truce of Calais.
The siege of Breteuil was the investment of the Norman town of Breteuil, held by partisans of Charles II, King of Navarre, by French forces. It lasted from April to about 20 August 1356. It was interrupted on 5 July when a small English army commanded by Henry, Earl of Lancaster relieved and resupplied it. The French king, John II, attempted to bring Lancaster to battle with the much larger French royal army, but Lancaster marched away and the attempt failed. John then renewed the siege of Breteuil.
Amaury de Clisson (1304–1347), was a Breton knight who became the chief emissary for Jeanne de Penthièvre to the court of Edward III of England.
House of Montfort, Brittany
Kingdom of England 
Kingdom of France