Middle Ages
Throughout the 14th century, French kings sought to expand their influence at the expense of the territorial holdings of the nobility. They ran into difficulties when attempting to confiscate the holdings of the English kings in southern France, leading to the Hundred Years' War, waged from 1337 to 1453. Early in the war the English under Edward III (r. 1327–77) and his son Edward, the Black Prince (d. 1376), won the battles of Crécy and Poitiers, captured the city of Calais, and won control of much of France. The resulting stresses almost caused the disintegration of the French kingdom during the early years of the war. In the early 15th century, France again came close to dissolving, but in the late 1420s the military successes of Joan of Arc (d. 1431) led to the victory of the French and the capture of the last English possessions in southern France in 1453. The price was high, as the population of France at the end of the Wars was likely half what it had been at the start of the conflict. Conversely, the Wars had a positive effect on English national identity, doing much to fuse the various local identities into a national English ideal. The conflict with France also helped create a national culture in England separate from French culture, which had previously been the dominant influence. The dominance of the English longbow began during early stages of the Hundred Years' War, and cannon appeared on the battlefield at Crécy in 1346.
Truce of Leulinghem
The Truce of Leulinghem was a truce agreed to by Richard II's kingdom of England and its allies, and Charles VI's kingdom of France and its allies, on 18 July 1389, ending the second phase of the Hundred Years' War. England was on the edge of financial collapse and suffering from internal political divisions. On the other side, Charles VI was suffering from a mental illness that handicapped the furthering of the war by the French government. Neither side was willing to concede on the primary cause of the war, the legal status of the Duchy of Aquitaine and the King of England's homage to the King of France through his possession of the duchy. However, both sides faced major internal issues that could badly damage their kingdoms if the war continued. The truce was originally negotiated by representatives of the kings to last three years, but the two kings met in person at Leulinghem, near the English fortress of Calais, and agreed to extend the truce to a twenty-seven years' period. Other provisions were agreed to, in attempts to bring an end to the papal schism, to launch a joint crusade against the Turks in the Balkans, to seal the marriage of Richard to Charles' daughter Isabella along with an 800,000 franc dowry, and to guarantee to continue peace negotiations, in order to establish a lasting treaty between the kingdoms. The treaty brought peace to the Iberian peninsula, where Portugal and Castile were supporting the English and French respectively. The English evacuated all their holdings in northern France except Calais.