How did the Crusades lead to the decline of feudalism?

The Crusades contributed to the decline of feudalism by fostering a sense of unity and shared purpose among European nations, which diminished the power of local lords. As knights and nobles left for the Crusades, their lands were often managed by others, leading to more centralized power and the rise of strong monarchies. Additionally, the increased trade and interaction with other cultures during the Crusades stimulated economic growth, encouraging a shift towards a more market-based economy that undermined the feudal system. This shift in social and economic structures ultimately weakened the traditional feudal hierarchy.