I find it interesting that when Islam first emerged it was seen as a force that would divide Christianity. It was viewed more as a military threat to the Christian nations than a religious threat. Most Christians believed that Islam would not last as a religion. When christians started to convert though, it became more of a threat in the eyes of the church, and so the writings about Muslims go more violent and hateful.

Dante's depiction of Muhammed is interesting. He definitely does not present Muhammed as a positive figure, he is n Hell, but he is not with the heretics in hell. He is with another figure Arius, who was seen as a divider of the church and was excommunicated both during his life and after his death. So, while Dante does think that Muhammed and Islam would divide Christians he does not place him with heretics.