What weapon made feudalism decline?

Answer 1

Conventional wisdom says that feudalism was pretty much ended by gunpowder.

Really, however, I am convinced that knights were made obsolete by the English longbow. Reading descriptions of the battles of Crecy and Agincourt, it is clear that trained archers could defeat knights rather easily. Comparison of the weapons shows that archers could fire more quickly, and had weapons that were just as deadly at any range. The only advantage the musket had was that archers were hard to train as a great deal of strength was involved.

Castles had been taken in one way or another before cannons came along. We do not read of many battles in which cannons were used against castles, and I am not sure whether they were effective in this regard or not. I have, however, read of castles that were made from rocks that would not shatter easily, and so cannons were not effective against them at all.

Also, the rise of the middle class and the end of serfdom in such places as England and Scotland preceded the introduction of muskets.