How did the crusades contribute to the end of europes medieval period

Fourth Crusade took out Eastern Roman Empire capital in 1204. With the Crusaders forming the Latin Empire in its place and pushing the Eastern Roman Empire into several kingdoms. It made the Greeks easy targets for the invading muslims. The empire however eventually reformed although it was considerably weaker. It eventually fell once again to the invading muslims using Hungarian weapons in 1453 thus marking the end of the middle ages. That and the muslims constantly stole the Roman Empire's technology and culture and claimed it for its own.
The Crsades brought large numbers of important Europeans into close and prolonged contact with the far more sophisticated Byzantine and Muslim civilizations of the Near East.Knowledge gained from this contact - in particular of Classical Greek and Roman texts long since lost or forgotten in Western Europe - was transmitted back to Europe and eventually helped start the Renaissance