The prophet Muhammad died in 632 CE. Within 100 years of his death, the Muslim empire had expanded to a great degree, reaching as far east as what is now Iran and as far west as Spain.
By 100 years after Muhammad's death, Islam's expansion was at a high point. In the west, Islam had spread across all of Northern Africa. It had even crossed the Straits of Gibraltar and Muslims dominated the Iberian Peninsula. This was as far as Islam was to penetrate into Europe as Muslim armies were defeated at the Battle of Tours in France in 732. By that time, Islam dominated everything from Morocco across Northern Africa to the Levant, the Arabian Peninsula, and the Persian Empire.