What English weapon destroyed the French at Agincourt in 1415?

The English weapon that largely made it possible to destroy the French at Agincourt in 1415 was the longbow. The Battle of Agincourt is notable for the use of the English longbow in very large numbers. The English and Welsh archers comprised nearly 80 percent of King Henry V's army.

King Henry V of England won a decisive victory in the Battle of Agincourt. On his accession to the throne of England in April 1413 Henry V resolved to revive the war against France and press his claim to the French throne. Outnumbered and outmanoeuvred, when Henry V won the Battle of Agincourt, it became a famous victory in the Hundred Years War between England and France. History points out that the win was all because of the humble longbow. In the lead up to the Battle of Agincourt, it looked as if King Henry V was leading his army to a major disaster.

With the victory in 1415, Henry V strengthened his position in his own kingdom. It legitimized his claim to the crown, which had been under threat after his accession.