The Hundred Years' War was not exactly one war, but rather was a series of armed, political conflicts between France and England between 1337 and 1453. Some historians break up the Hundred Years' War into three sections: the Edwardian War, the Caroline War, and the Lancastrian War. Throughout the entire series of conflicts, both sides were fighting over the right to rule France.

Technically speaking, "key events" of the Hundred Years' War began well before 1337, the year typically identified as the start of the War. Initial issues arose when Charles IV of France died in 1328, leaving no male heir to the throne. His sister, Isabella of France, was ruling England at the time, and she felt the French throne should go to her son, Edward III of England. French citizens and nobility, however, argued that Philip VI, Charles's first cousin, should claim the throne, as accession did not go through female relatives (i.e., through Isabella).

Initially, Edward and Isabella accepted Philip's reign, but tensions increased over time as the two kingdoms encountered political disagreements. The final key disagreement that led to the start of the Hundred Years' War occurred on May 24th, 1337, when Philip declared that Edward had effectively forfeited Aquitaine (a region of France) by harboring Robert III of Artois, a former adviser to Philip who tried to steal inheritance by committing forgery. In response, Edward renewed his claim to the throne of France, and thus began the Hundred Years' War.

Key events during the war include the following:

1. Battle of Crecy (1346)
2. Battle of Poitiers (1356)
3. Treaty of Bretigny (1360)
4. Death of Black Prince (1376)
5. Battle of Agincourt (1415)
6. Treaty of Troyes (1420)
7. Siege of Orleans and Rise of Joan of Arc (1429)
8. Battle of Castillon (1453)

Throughout the Hundred Years' War, each side saw victories and setbacks, though the Battles of Crecy, Poitiers, and Agincourt were all considered victories for England. The Treaty of Bretigny (later ratified as the Treaty of Calais) was intended to create peace, as Edward III renounced his claim to the throne of France in return for the restoration of Aquitaine under his reign, but conflict persisted nonetheless. Shortly after the treaty was signed, Edward made his son Edward of Woodstock (referred to as the Black Prince) the Duke of Aquitaine.

During the next 55 years, localized fighting and political disagreements between the two countries continued throughout France until finally, war broke out at the Battle of Agincourt. Once again, England saw victory in this battle, and the country used that victory as ammunition to further stake their claim over various French regions. Eventually, after a series of successful military campaigns, England was able to convince France that, after the death of their current king( Charles VI), Henry V's heirs would inherit the French throne. This was the Treaty of Troyes.

The "peace" thought to be brought by the Treaty of Troyes was short lived, as Henry V died within the next two years, and his only heir was not even 9 months old. Nevertheless, the baby, Henry VI, was crowned king of both England and France. This was not accepted by much of French nobility, and so continued the Hundred Years' War.

At this point, almost all of northern France and much of southwest France were under control of England, but the English continued to seek more territory. They began the siege of Orleans in 1428 in an attempt to conquer one of the last remaining cities still loyal to France. It was in the midst of this fighting that the famed Joan of Arc rose to notoriety. The teenager claimed to have seen visions of saints who told her support France in the fight against England. She was ultimately tried for heresy and sentenced to death.

About twenty years after the death of Joan of Arc, the final battle of the Hundred Years' War, the Battle of Castillon, took place in Gascony. This battle was considered the first major victory for France, who had previously been defeated by England in all of the war's major conflicts. As a result of the battle, England lost reign over all French territories except for Calais. The battle effectively weakened the English military, and though some conflict continued in the years after Castillon, it is in hindsight considered the definitive end of the Hundred Years' War.