In what year did the Hundred Years' War begin?

The Hundred Years' War began in 1337.

The name describes a long, intermittent series of conflicts between England and France, conventionally dated from 1337 to 1453. It was not one continuous war: truces, political crises, and the Black Death repeatedly interrupted fighting. Even so, 1337 is the standard starting year used by historians and quiz references.

The immediate trigger came when King Philip VI of France confiscated Edward III of England's French possessions, especially Gascony, in May 1337. Edward responded by asserting a claim to the French throne through his mother, Isabella of France, the sister of the late King Charles IV.

The conflict's first major phase, often called the Edwardian War, ran from 1337 to 1360. English victories at Crécy in 1346 and the capture of Calais in 1347 followed. The war eventually ended with a French victory in 1453, although England retained Calais for another century. Thus, the title is a rounded label for 116 years of intermittent warfare, not exactly one uninterrupted century.