What is the catalyst that led to the Renaissance?

What is the catalyst that led to the Renaissance?

The Crusades (1095-1291) were the catalyst that led to the Renaissance. The Crusades or the Holy Wars were a series of several military campaigns led by the Catholic Church to take the Holy Land and Jerusalem from the Muslims.
The First Crusade was launched in 1095 by Pope Urban II. It was a major turning point in the expansion of Western power, and was the only crusade to capture Jerusalem.
The Crusades initially started as an appeal to the French knightly class. But it soon turned into a conquest of territory outside of Europe, such as the Fourth Crusade against Constantinople. Although it did not capture Jerusalem, it managed to establish a Roman Christian kingdom there that lasted till 1262. None of the crusades that followed were successful.
But the historic significance of the Crusades was not that it was a series of defeats, but that it brought Europe in contact with the East. Although the original aim of liberating Jerusalem failed to materialize, it opened up a new world and widened the outlook of the Europeans. This provided the base for a cultural rebirth or renaissance