There were many causes of the crusades including political, economic, and religious factors. However, the crusades were a major conflict between European Christian forces and Muslim armies from Western Asia who fought for control of the Holy Lands that had importance to both Christians in Muslim. The control of these lands brought power, prestige, religious importance, and also economic gains to whichever force controlled these lands.
It's greatly reduce the morale of the central power
Answer:
C. Forced labor of Native Americans in the Spanish colonies.