Earlier generations of European scholars believed that conversion to Islam were made by the point of the sword, and that conquered peoples were given the choice of conversion or death. So a lot of, according to Ira Lapidus, these early European scholars viewed it analogous to things like the Spanish Inquisition, or some aspects of the Crusades, or some of what we saw in the New World on Quistodors, where it really was convert or die. But according to Lapidus, it is now apparent that conversion by force, while not unknown in Muslim communities, so in Muslim countries, so there was some forced conversion, but according to Lapidus, was in fact rare. Muslim conquerors ordinarily wished to dominate rather than convert, and most conversions to Islam were voluntary. In most cases, worldly and spiritual motives for conversion blended together. And other sources I've looked at do hint at these early caliphates weren't that interested in conversion. They were clearly Muslim, and they were also Arab-dominated, and they liked having this elite Arab Muslim ruling class, and they weren't that interested in spreading the religion, and only when we get into the Abbasid Caliphate, where it becomes more multicultural and more Muslim and less Arab-focused, that you start to have more and more conversions.