In 1453 the English and the French fought for the last time at the Battle ofCastillon. The French annihilated a charge of English knights using their new cannons, which brought the Hundred Years' War and the era of knights and castles to an end.
It is important because knowing for yourself is much better than leaning on other people, or the internet for support. It would be very hard to have an opinion about something, or even have a conversation without having an understanding of it first.