The state of Muslim nations after World Wars I and II, along with the reciprocal rise of Western powers due to their technological, military, and economic advancements, saw a reversal of the flow emigrants between the two worlds. There had been a period of considerable length of time when the flow had been in the opposite direction, that is, from West towards the East. People from all over Europe used to come to Muslim lands to learn various sciences, such as mathematics, astronomy, medicine, etc. But now the trend had been reversed.