Answer:
The Crusades were initiated by the Catholic Church in order to gain control of Jerusalem again, as it has fallen into the hands of the Muslims. While the Catholic Church had its goals in conquering Jerusalem, including wealth and power, it didn't foresee that the organizing of the Crusades it's going to actually backfire on it and make the biggest blow to it.
The Crusades themselves had mixed outcomes, sometimes winning, sometimes losing. What had a much greater effect was that the Crusaders managed to bring in Europe a lot of things from Asia which turned out to change the course of history.
Because the Crusaders were in constant contact with the Muslims, they brought in numerous technological advancements in Europe. Also, through them, some of the ancient literature from Greece and Rome came back to Europe.
This prompted a huge interest among the people, especially the ones higher in the hierarchy, as they saw the potential of the new technology, but also the potential for the future based on the ancient literature. The end result was a technological boom in Europe, a loss of power by the Catholic Church, the Age of Discoveries, or all put in one, the Renaissance.
Explanation:
