The Hundred Years' War was a series of conflicts fought between England and France from 1337 to 1453. The war had a significant impact on the decline of feudalism in Western Europe because it weakened the power of the feudal lords and their ability to control their lands and subjects.
During the war, both sides conscripted large numbers of soldiers from the nobility and common people, which reduced the number of able-bodied men available to work the land and pay feudal dues. This led to a decline in agricultural production and a decline in the wealth and power of the feudal lords.
In addition, the constant fighting and destruction caused by the war disrupted trade and commerce, which further weakened the feudal system. As a result, the feudal lords' authority over their subjects decreased, and the power of the central governments in England and France grew.
Overall, the Hundred Years' War contributed to the decline of feudalism in Western Europe by undermining the power of the feudal lords and by disrupting the economic and social structures that supported the feudal system.