The Hundred Years' War: A Summary

The Hundred Years' War was a series of conflicts waged from 1337 to 1453, that pitted the House of Plantagenet, rulers of the Kingdom of England, against the House of Valois for control of the French throne. Each side drew many allies into the war.

The war had its roots in a dynastic disagreement dating back to the time of William the Conqueror, who became King of England in 1066 while retaining possession of the Duchy of Normandy in France. As the rulers of Normandy and other lands on the continent, the English kings owed feudal homage to the King of France.  In 1337, Edward III of England refused to pay homage to Philip VI of France, leading the French King to confiscate Edward's lands in Aquitaine.

Edward responded by declaring himself to be the rightful King of France rather than Philip, a claim dating to 1328 when Edward's uncle, Charles IV of France, died without a direct male heir. Edward was the closest male relative of the dead king, as son of Isabella of France who was a daughter of Philip IV of France and a sister of Charles IV. But instead, the dead king's cousin, Philip VI, the son of Philip IV's younger brother, Charles, Count of Valois, had become King of France in accordance with Salic law, which disqualified the succession of males descended through female lines. The question of legal succession to the French crown was central to the war over generations of English and French claimants.

Historians commonly divide the war into three phases separated by truces: 1) the Edwardian Era War (1337-1360); 2) the Caroline War (1369-1389); and 3) the Lancastrian War (1415-1453).

Contemporary conflicts in neighboring areas, which were directly related to this conflict included the War of the Breton Succession (1341–1364), the Castilian Civil War (1366–1369), the War of the Two Peters (1356–1375) in Aragon, and the 1383-85 Crisis in Portugal.  Later historians invented the term "Hundred Years' War" as a periodization to encompass all of these events, thus constructing the longest military conflict in history.

The war owes its historical significance to multiple factors. By its end, feudal armies had been largely replaced by professional troops, and aristocratic dominance had yielded to a democratisation of the manpower and weapons of armies. Although primarily a dynastic conflict, the war gave impetus to ideas of French and English nationalism. It saw the wider introduction of weapons and tactics that supplanted the feudal armies where the use of heavy cavalry had dominated. The first standing armies in Western Europe since the time of the Western Roman Empire originated during the war, composed largely of commoners and thus helping to change their role in warfare. With respect to the belligerents, English political forces over time came to oppose the costly venture; while the dissatisfaction of English nobles, resulting from the loss of their continental landholdings, became a factor leading to the civil wars known as the Wars of the Roses (1455–1487).  In France, civil wars, deadly epidemics, famines and bandit free-companies of mercenaries reduced the population drastically.

http://en.wikipedia.org/wiki/Hundred_Years%27_War