How did the Hundred Years’ War contribute to the decline of the medieval era?

The Impact of the Hundred Years' War The Hundred Years' War contributed to the decline of feudalism by helping to shift power from feudal lords to monarchs and to common people. During the struggle, monarchs on both sides had collected taxes and raised large professional armies.

Explanation:

It led to the collapse of the feudal system.

Explanation:

Quoting Pearson World History:

The Hundred Years' War brought many changes to the late medieval world. The longbow and cannon gave common soldiers a new importance on the battlefield and undermined the value of armored knights on horseback. Although neither nobles nor commoners knew it then, feudal society was changing and medieval Europe was coming to an end. Knights and castles were doomed to disappear. Strong monarchs needed large armies, not feudal vassals, to fight their wars.