Answer:
By convention, the Hundred Years' War is said to have started on May 24, 1337, with the confiscation of the English-held duchy of Guyenne by French King Philip VI. This confiscation, however, had been preceded by periodic fighting over the question of English fiefs in France going back to the 12th century.
Part of: 15th century
Includes event: Battle of Crécy, Siege of Orléans