How did knights affect the decline of feudelism?

When feudalism started to decline, it did affect knights. Knights were pretty high in the ranking of all the classes. They lived in fair houses, and lived pretty descent lives as a knight. The problem was when they fought in battles and wars. The problem was that longbows were discovered. This was very bad news for knights. That's because when armies used longbows, the arrows or spears had so much power and speed, that they could pierce straight through the armor of a knight. Therefore, when there were battles, knights were no longer the first in mind, because they weren't as indestructible anymore.