The Hundred Years' War refers to a series of military conflicts between France and England over disputed territory. The two regions had a complex and intertwined relationship: in 1066, the English crown had passed into the hands of a Norman (French) monarch, William the Conqueror. As a result, for the next 300 hundred years, English kings also held some amount of French territory, which made them simultaneously monarchs on par with the rulers of France, but also the equivalent of French lords who were expected to serve the French kings. The French territories occupied by the English were constantly shifting as land was conquered and reconquered. Marriages between both royal houses and important noble families made these relationships even more complicated.
In 1316, a law was passed that forbade women from succeeding to the French throne. This quickly created problems when, in 1328, the French King Charles IV died with no male heirs. His closest relative was his nephew, King Edward III of England (Edward was the son of Isabella, a French princess and sister to Charles IV). However, with the ban on female succession and general distrust of a foreign ruler taking the throne, the French crowned Philip, Count of Valois, as King Philip IV (he was a cousin of Charles IV). At first, Edward III did not contest this claim, but he and Philip did not get along well, getting into disputes over territory held by the English crown. In 1337, Edward III formerly asserted his right to the French crown, marking the start of the war.
At first, the English won significant battles, especially since Edward III's eldest son—known as Edward, the Black Prince—was an impressive military leader. However, the war was expensive and exhausting, especially with both English and French forces simultaneously involved in other military conflicts and suffering the effects of the Black Plague, which broke out in 1348 and resulted in a huge death toll in both countries. In 1360, Edward III and King John II of France (who had succeeded his father Philip) signed a treaty dividing up the disputed territory; Edward also renounced his claim to the French throne.
In 1369, warfare resumed when the Black Prince tried to levy an unpopular tax on the residents of his French territories. They appealed to the French king, Charles V (he had succeeded to the throne in 1364). Edward III reasserted his claim to the French throne, and this portion of the war lasted until 1389. By this time, the English throne was occupied by Richard II, who had inherited it after both his father and elder brother (the Black Prince died), and the French throne was held by Charles VI, who had become King at the age of 11, with power largely held by a series of regents (temporary rulers). Internal conflicts and difficulties financing the war led to a significant decline in hostilities.
While fewer battles were fought against the English after 1389, important internal tensions arose in France. Charles VI suffered from bouts of madness, which created an opportunity for others to struggle for power. His uncle, the Duke of Burgundy, led one faction struggling for control, while the King's brother, Louis of Valois, led another faction. Over time, these two camps would become known as the Burgundian and Armagnac forces. Charles the Dauphin (later Charles VII, who appears in Shaw's play) was born into a world where his father was an ineffectual king, and France was effectively in a state of civil war. Meanwhile, a new English king, Henry V, had come to the throne in 1413, and he knew that these internal struggles left France vulnerable. He declared war in 1414, seeking to reclaim territory that had previously been lost, and in 1415, the English forces won a major victory in the Battle of Agincourt.
Under Henry V's leadership, the English formed an allegiance with the Burgundians and continued to win back territory. They were so successful that in 1420, Henry V and Charles VI signed the Treaty of Troyes. Henry was to marry Charles's daughter Catherine, and Henry's heirs became the heirs to the French throne. To facilitate this transition, the Dauphin Charles was declared illegitimate, despite being the expected heir to the throne. The English occupied Paris, and it seemed that their hold on France was invincible. However, by 1422, both of the kings who had signed this treaty were dead. The English crown passed to Henry VI, who was an infant, and the French crown hung in limbo, with the Dauphin Charles uncrowned and unclear in status. The territories held through the English-Burgundian alliance were considered the possession of Henry VI.
Joan's interventions in 1429 and 1430 led to Charles being crowned as Charles VII, and to significant gains by the French forces. While the war continued for a long time after Joan's execution, Charles VII grew into a capable military leader. In 1435, the Burgundians switched their allegiance to side with Charles VII, and in 1436, the French were able to capture Paris. The war was not formally ended by treaty until 1474, but it had effectively ended years before, with England preoccupied with the internal conflict known as the Wars of the Roses. By the end of the war, the only French territory held by the English was the city of Calais, which it would hold until1558.
