I would say trading cities became more important
A, B, and C. Mesopotamia was in the middle of a desert, and the only reason it was farmable was because it lay between the Tigris and Euphrates rivers which flooded yearly to water the ground.
Answer: Pope Urban II launches the Crusades by calling all Christians in Europe to war against Muslims in order to reclaim the Holy Land.
SEARCH IT UP ON YOUR DEVICE AND YOU WILL GET IT RIGHT 99% SURE