Would it be possible for a form of Christianity, to arise in the middle east, perhaps centered around former Judaea, that does not recognize the authority of the Catholic Church or the Popes, and in fact, actively opposes it.
I Was thinking this denomination could arise alongside the Catholic Church, eventually becoming rivals for the allegiances of Jesus' followers.
Perhaps if we butterfly Islam?
If so, perhaps the Crusades could be replaced with a series of wars between Catholicism and this Variant of Christianity