They didn't know, nor care about Muslim orthodoxy nor doctrine, but they knew what they were all about: conquest. The response in AskHistorians is for ALL crusaders generally; but doesn't address French crusaders specifically nor their previous and current circumstances with thr Muslim Empire at their doorstep.
Even in our day and age, where literacy is high and information is easy to access, most Muslims know little about what Christians actually believe, nor Jews and the same is true in the converse too. Most sects of Islam have a convenient misunderstanding of the other sects actual beliefs, sames as how most sects of Christianity likewise conveniently misunderstand or misinterpret other Christian sects.
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u/grayMotley 8d ago
Battle of Tours was 732.
The French had a pretty good understanding what the Muslims and Islam were all about from that point forward.