Answer:
The entire structure of European society changed during the 12th and 13th centuries, and there was a time when this change was attributed largely to the Crusades. Historians now, however, tend to view the Crusades as only one, albeit significant, factor in Europe’s development. It is likely that the disappearance of old families and the appearance of new ones can be traced in part to the Crusades, but generalizations must be made with caution. It should, moreover, be remembered that, while some Crusaders sold or mortgaged their property, usually to ecclesiastical foundations, others bequeathed it to relatives. The loss of life was without doubt considerable; many Crusaders, however, did return to their homes.
Step-by-step explanation:
There can be little doubt that the Crusades slowed the advance of Islamic power, although how much is an open question. At the very least, they bought Europe some much-needed time. Without centuries of Crusading effort, it is difficult to see how western Europe could have escaped conquest by Muslim armies, which had already captured the rest of the Mediterranean world.