The 100 year war took place from 1337 to 1453. This was not 1 long war, it was a series of wars divided by broken treaties.
Many knights died fighting for their land.
King Philip VI of France decided to capture Guyenne, England. This sparked the war and from there it was on.
The English would achieve victory in these battles as a result of the new longbow.
After the death of Joan's death the French Army took advantage and was able to drive the British Army out. They won the 100 year war after so much fighting. The war contributed to decline of feudalism, as castles were not effective. France had developed a strong military during the war.