English offensives in 1345–1347, during the Hundred Years' War, resulted in repeated defeats of the French, the loss or devastation of much French territory and the capture by the English of the port of Calais. The war had broken out in 1337 and flared up in 1340 when the king of England, Edward III, laid claim to the French crown and campaigned in northern France. There was then a lull in the major hostilities, although much small-scale fighting continued.
Edward determined early in 1345 to renew full-scale war and personally led the main English army to northern France. Edward delayed its disembarkation, and his fleet was scattered by a storm, ruining this offensive. He also despatched a small force to Gascony in south-west France under Henry, Earl of Derby, which was spectacularly successful. The following spring a large French army, led by the heir to the French throne, John, Duke of Normandy, counter-attacked Derby's forces.
Edward responded by landing an army of 10,000 men in northern Normandy. The English devastated much of Normandy and stormed and sacked Caen, slaughtering the population. They cut a swath along the left bank of the Seine to within of Paris. The English army then turned north and inflicted a heavy defeat on a French army led by their king, Philip VI, at the Battle of Crécy on 26 August 1346. They promptly exploited this by laying siege to Calais. The period from Derby's victory outside Bergerac in late August 1345 to the start of the siege of Calais on 4 September 1346 became known as Edward III's (year of marvels).
After an eleven-month siege, which stretched both countries' financial and military resources to the limit, the town fell. Shortly afterwards, the Truce of Calais was agreed; it ran for nine months to 7July 1348, but was extended repeatedly until it was formally set aside in 1355. The war eventually ended in 1453 with the English expelled from all French territory except Calais, which served as an English entrepôt into northern France until 1558.
Background
Since the Norman Conquest of 1066, English monarchs had held titles and lands within France by inheritance. Their possession made them vassals of the kings of France. The status of the English king's French fiefs was a major source of conflict between the two monarchies throughout the Middle Ages. French monarchs systematically sought to check the growth of English power, stripping away lands as the opportunity arose. Over the centuries, English holdings in France had varied in size, but by 1337 only Gascony in south western France and Ponthieu in northern France were left. The Gascons preferred their relationship with a distant English king who left them alone to one with a French king who would interfere in their affairs. Following a series of disagreements between Philip VI of France () and Edward III of England (), on 24 May 1337 Philip's Great Council in Paris agreed that Gascony and Ponthieu should be taken back into Philip's hands on the grounds that Edward was in breach of his obligations as a vassal. This marked the start of the Hundred Years' War, which was to last 116 years.
Although Gascony was the cause of the war, Edward was able to spare few resources for it, and whenever an English army campaigned on the continent during the first eight years of the war it operated in northern France. In 1340, Edward laid formal claim to the Kingdom of France, as the closest male relative of Philip's predecessor, Charles IV. He then led an inconclusive and vastly expensive campaign against Tournai, after which there was a relative lull in the fighting, formalised in the Truce of Espléchin the same year.
Plans Edward determined early in 1345 to renew full-scale war and to attack France on three fronts: William, Earl of Northampton, would lead a small force to Brittany, a slightly larger force would proceed to Gascony under the command of Henry, Earl of Derby, and the main force would accompany Edward to either northern France or Flanders. The previous Seneschal of Gascony, Nicholas de la Beche, was replaced by the more senior Ralph, Earl of Stafford, who sailed for Gascony in February with an advance force.
French intelligence had uncovered the English plan for offensives in the three theatres, but France did not have the money to raise a major army in each. The French anticipated, correctly, that the English planned to make their main effort in northern France. Thus they directed what resources they had there, planning to assemble their main army at Arras on 22July. South-western France was encouraged to rely on its own resources, but as the Truce of Malestroit, signed in early 1343, was still in effect, the local lords were reluctant to spend money and little was done.
1345 Edward's main army sailed on 29 June. They anchored off Sluys in Flanders until 22July, while Edward attended to diplomatic affairs. When they subsequently sailed, probably intending to land in Normandy, they were scattered by a storm and found their way to English ports over the following week. After more than five weeks on board ship, the men and horses had to be disembarked. There was a further week's delay while the King and his council debated what to do, by which time it proved impossible to take any action with this force before winter. Aware of this, Philip despatched reinforcements to Brittany and Gascony. Peter, Duke of Bourbon was appointed commander-in-chief of the south-west front on 8August.
Gascon campaign
Derby's force embarked at Southampton at the end of May 1345. Bad weather forced his fleet of 151 ships to shelter in Falmouth for several weeks en route, finally departing on 23July. The Gascons, primed by Stafford to expect Derby's arrival in late May and sensing the French weakness, took the field without him. The Gascons captured the large, weakly garrisoned castles of Montravel and Monbreton on the Dordogne in early June; both were taken by surprise and their seizure broke the tenuous Truce of Malestroit. Stafford carried out a short march north to besiege Blaye. He left the Gascons to prosecute this and proceeded to Langon, south of Bordeaux, to set up a second siege. The French issued an urgent call to arms.
Meanwhile, small independent parties of Gascons raided across the region. Local French groups joined them, and several minor nobles threw in their lot with the Anglo-Gascons. They had some successes, but their main effect was to tie down most of the French garrisons in the region and to cause them to call for reinforcements – to no avail. The few French troops not garrisoning fortifications immobilised themselves with sieges of English-controlled fortifications: Casseneuil in the Agenais; Monchamp near Condom; and Montcuq, a strong but strategically insignificant castle south of Bergerac. Large areas were left effectively undefended.
On 9August Derby arrived in Bordeaux with 500 men-at-arms, 1,500 English and Welsh archers, 500 of them mounted on ponies to increase their mobility, and ancillary and support troops, such as a team of 24 miners. The majority were veterans of earlier campaigns. After two weeks of further recruiting and consolidation of his forces Derby decided on a change of strategy. Rather than continue a war of sieges he determined to strike directly at the French before they could concentrate their forces. The French in the region were under the command of Bertrand de l'Isle-Jourdain, who was assembling his forces at the communications centre and strategically important town of Bergerac. This was east of Bordeaux and controlled an important bridge over the Dordogne River.
Derby's offensive
Derby moved rapidly and took the French army by surprise in late August 1345, ambushing its cavalry component outside Bergerac and then driving its panicking infantry back to the town. French casualties were heavy, with many killed and a large number captured, including their commander. The surviving French rallied around John, Count of Armagnac, and retreated north to Périgueux, the provincial capital. Within days of the battle, Bergerac fell to an Anglo-Gascon assault and was subsequently sacked. After consolidating and reorganising for two weeks Derby left a large garrison in the town and moved north to Périgueux, taking several strong points on the way.
During September, John, Duke of Normandy, the son and heir of Philip VI, gathered an army reportedly numbering more than 20,000 men and manoeuvred in the area. In early October a very large detachment drove off Derby's force, which withdrew towards Bordeaux. Further reinforced, the French started besieging the English-held strong points. A French force of 7,000, commanded by Louis of Poitiers, besieged the castle of Auberoche, east of Périgueux. After a night march Derby attacked the French camp on 21October while they were at dinner, taking them by surprise and causing heavy initial casualties. The French rallied and there was a protracted hand-to-hand struggle, which ended when the commander of the small English garrison in the castle sortied and fell upon the rear of the French. They broke and fled. French casualties are described by modern historians as "appalling", "extremely high", "staggering", and "heavy". Many French nobles were taken prisoner; lower ranking men were, as was customary, killed on the spot. The French commander, Louis of Poitiers, died of his wounds. Surviving prisoners included l'Isle-Jourdain, the second in command, two counts, seven viscounts, three barons, the seneschals of Clermont and Toulouse, a nephew of the Pope and so many knights that they were not counted.
The four-month campaign has been described as "the first successful land campaign of... the Hundred Years' War", which had commenced more than eight years earlier. Modern historians have praised the generalship demonstrated by Derby in this campaign: "superb and innovative tactician"; "ris[ing] to the level of genius"; "brilliant in the extreme"; "stunning"; "brilliant". A chronicler writing fifty years after the event described him as "one of the best warriors in the world".
1346 Siege of Aiguillon
For the 1346 campaigning season Duke John was again placed in charge of all French forces in south-west France. In March a French army of between 15,000 and 20,000, enormously superior to any force the Anglo-Gascons could field, marched on the Anglo-Gascon-held town of Aiguillon and besieged it on 1April. On 2April an arrière-ban, a formal call to arms for all able-bodied males, was announced for southern France. French national financial, logistical and manpower efforts were focused on this offensive.
Crécy campaign
During the first six months of 1346 Edward again gathered a large army in England. The French were aware of this, but given the extreme difficulty of disembarking an army other than at a port, the English no longer having access to a port in Flanders, but with friendly ports in Brittany and Gascony, they assumed Edward would sail for one of the latter; probably Gascony, in order to relieve Aiguillon. To guard against any possibility of an English landing in northern France, Philip VI relied on his powerful navy. This reliance was misplaced as his navy was late assembling and in any event would have been unable to effectively patrol the whole Channel. Edward's army embarked in the largest fleet ever assembled by the English to that date, 747 ships. The French were unable to prevent Edward successfully crossing the Channel and landing at St. Vaast la Hogue on 12 July, from Cherbourg in northern Normandy. The English army was approximately 10,000 strong and it achieved complete strategic surprise. Philip recalled his main army, under Duke John, from Gascony. After a furious argument with his advisers, and according to some accounts his father's messenger, John refused to move until his honour was satisfied by the fall of the Aiguillon.