One of the many effects of the Crusades was that the pope and the kings of Western Europe became more powerful. In addition, Europeans began to trade with the Middle East. Trade increased as Western Europeans began to buy products like sugar, lemons, and spices. Naturally, increased trade led to increased cultural diffusion.
I think it was because dynastic rulers were so caught up with war that they had to let china have a time of peace so they could focus on wining their wars. I hope i helped you out!
