The causes of the war include French threats to English holdings on the continent and PhilipVI's aid to David Bruce when he was driven out of Scotland.
In reply Edward III gave shelter to Robert of Artios, Philip VI's exiled cousin. Edward III also formed alliances with the nobles of the Netherlands and Emperor Louis the Bavarian.
Philip VI began the hostilities by declaring all English lands on the continent forfeit to the crown of France and by sending a fleet to raid the south coast of England. In response Edward III raised a claim to the throne of France.
During 1339 & 1340 Edward III led two unsuccessful land campaigns through northern France from the Netherlands. The French adopted a policy of refusing to commit to battle in the open and only defending fortified towns. The only decisive battle during this time was the English naval victory a Sluys on June 24, 1340. Where the French fleet was destroyed. Ensuring English sea supremacy for 30 years.
After the 1340 campaign Edward III abandoned attempts to attack France from the Netherlands. Next Edward III supported John of Montfort in an unsuccessful campaign in Brittany. In so doing Edward gained possession of many of the Breton castles. With no decisive victories on either side thing quieted down, leading to a truce that was in effect from March 1343 to March 1345.
In 1346 Edward III adopted a new policy of attacking into France with a purely English army. In July Edward III landed in Normandy and marched forth on a raid that extended up the Seine almost to Paris. The French army made its appearance and Edward retired to the north towards Flanders, pursued by the French. After crossing the Somme river Edward stopped to face the French at Crecy near Abbeville. The result being the Battle of Crecy Aug. 26, 1346. After his victory at the battle of Crecy Edward III besieged Calais for almost a year, Calais surrendering on Aug. 4, 1347.
The war next entered an inactive phase due to the arrival in England and France of the Black Death in 1348. This quiet period was extended by the death of Philip of Valios in 1350. The only break in the calm was In 1351 when Edward III defeated an attack upon Calais by nobles from Picardy that was unsupported by the government in Paris. Various Truces kept things quiet till 1355.
A pattern of English raids into the heart of France began in 1355. The most successful of these leading to the Battle of Poitier Sept. 19, 1356. The French defeat at Poitier led to the signing in March 1359 of the Treaty of London. The French Estates General refused to ratify the Treaty. As a result Edward III led the largest English army yet from Calais on a raid that devastated all of Northern France as far as Rheims and the border of Burgundy. The campaign continued through the winter, ending before the Gates of Paris. This forced the French Regent Charles to agree to all of Edward's terms and sign the Peace of Bretigny on May 8, 1360. Under the terms of the treaty Edward III gave up his claim to the Throne of France. The French would ransom King Jean for 3,000,000 gold crowns. Also lands would be ceded to Edward III that would reconstitute the Duchy of Aquitane, to include 1/2 of France South of the Loire, also Northern France, Calais, and the counties of Guienne and Ponthieu. All these lands were exempted from vassalage to the French Throne.
In 1364 Charles the V succeeded Jean II upon his death. Edward the Black Prince was made Duke of Aquitane and things were peaceful until 1367 when Edward the Black Prince led a campaign into Castille and defeated Henry of Trastamara at the battle of Najera. As a result of this campaign, high taxes were imposed upon the Duchy of Aquitane. The people of the Duchy appealed to Charles V for relief and Edward III was ordered to appear before the French Parliament. Edward refused. Charles V declared Aquitane forfeit to the French crown for treason and rebellion. Edward III replied by reclaiming the throne of France. Hostilities reopened in 1369.
Due to Edward III's age and the illness of Edward the Black Prince the leadership of the war fell to John of Gaunt. John was no match for the leadership of the French Constable Bertrand du Guesclin. By 1370 the French had captured Poitou, Quercy, and Rouergue. Henry of Trastamara captured Castille and in 1372 the combined Spanish and French fleets defeated the English fleet at the naval battle of La Rochelle. Passage to and from the continent was now unsafe and the combined fleets raided Kent, Sussex, Devon, and Cornwall. The English continued to conduct raids through French territories to little effect. By 1374 little was left of the English possessions in France, save Calais and a coastal strip between Bordeaux and Bayonne. A truce was signed at Bruges in Jan. 1375 that held until just before Edward III's death on June 12, 1377.
Edward was succeeded by his grandson Richard, who was but nine years of age. The English continued to conduct raids through French territories with little effect. Charles V and Constable Bertrand du Guesclin both died in 1380. At this time England was caught up in a period of internal conflict and the war in France ground to a halt.
The Treaty of Paris was signed in 1396 that granted a 30 year peace. Allowed the English retain Calais and the coastal strip between Bordeaux and Bayonne. The terms also arranged the marriage of Richard II to Isabelle the daughter of Charles the VI. Due to increased internal warfare Richard II was forced to abdicated the throne. Henry of Bolingbroke claimed the vacant throne and was crowned Henry IV on Oct. 13 1399.
The next combat began in 1403 when the Duke of Orleans entered Guienne while a French fleet attacked and burnt Plymouth. In 1407 Louis, Duke of Orleans was murdered by John, Duke of Burgundy. The loss of the leader of the French war party ended this phase of the Anglo-French conflict.
Next France experienced a period of civil war between the forces of Orleans and Burgundy.
On March 20, 1413 Henry IV died and was succeeded by his son Henry of Monmouth. Henry V set about to take advantage of the civil war in France and planned a campaign for the fall of 1415. Just prior to sailing for France on Aug. 10, 1415 a plot by Richard, Earl of Cambridge, Lord Scrope, and Sir Thomas Grey to overthrow the crown in favor of the Earl of March was uncovered when the Earl of March heard the plans and revealed them to the King. The plotters were executed and 5 days later Henry sailed for France. Henry V landed at the mouth of the Seine and laid siege to the town of Harfleur. With no help coming from the Orleans camp Harfleur surrendered. Winter was fast approaching and Henry V decided to withdraw to Calais. He was intercepted by the French army. The result was the Battle of Agincourt, Oct. 25, 1415. This defeat heralded the end of resistance from the Crown for years. In July 1417 Henry V landed at the mouth of the Seine with 17,000 men and proceeded to conquer Normandy with no interference from the French Crown. By 1418 the last major city Rouen was besieged and fell on Jan. 19, 1419. The Treaty of Troyes gave Henry sovereignty over all the lands he had conquered, and his marriage to Catherine Daughter of Charles VI made him heir to the throne of France. Henry V continued to Successfully fight the forces of the disinherited Dauphin until his death in 1422.
Upon his death Henry V was succeeded by his 2 year old son Henry VI. Charles VI died only three months later and the Dauphin declared himself Charles VII. John of Bedford was named regent in France and continued the war defeating the forces of Charles VII at the battles of Cravant in 1423 and Verneuil in 1424 with the aid of Philip of Burgundy. Now entered Joan of Arc. Forces led by her broke the siege of Orleans in 1429. This was followed by the French victories at Jarqeau, Beaugency and the Battle of Patay on June 19, 1429.
In 1435 the Duke of Burgundy made peace with Charles VII in the Treaty of Arras. This doomed any chance England had to win the war. Shortly thereafter John of Bedford died at Rouen. Paris fell to Charles in April 1436.
The English continued to fight on for 8 years and held onto Normandy.
In 1444 the English council signed a 2 year truce with Charles. This truce was extended several times and lasted until 1449. In June 1449 Charles invaded Normandy and conquered the Duchy in a campaign lasting only a few months. The last English force to cross to the continent was defeated at the battle of Formigny Apr. 15, 1450. The Duke of Sommerset retreated to Caen and held out there for two more months. Brodeaux fell on June 30, 1451, Bayonne capitulated on Aug. 20th. This ended the conflict in France.
The next three years brought more unrest to England, leading up to the War of the Roses.