In the war of the English and the French the wore chain armor. The French also used cannons and swords and some road horses. The cannons ended up just scaring the horses and if men got in the way of the men on horses the men on horses would run them over.
The Canon's and the Horses
In the war of the English and the French the English wore good armor and had an advantage even though they were outnumbered. The English used longbows and the English were also organized in battle.
Due to the English using longbows the French's chain armor became useless. The longbows made the the chain armor useless because they shot right through it.
The Canon's the French used ended becoming useless except for scaring they're own horses.