Global Regents soon and i dont know crusades?

Question: Global Regents soon and i dont know crusades!?

i cant find anything about them anywhere
can someone please explain them
just brief me on themWww@QuestionHome@Com

Best Answer - Chosen by Asker:

all you need to know about the crusades is that it was a series of religious wars between muslims and christians over the holy land of jerusalem!.!.!. modern day israelWww@QuestionHome@Com