There's also the sense that we're at the very beginning of a long decline for the Byzantine Empire. So one thesis could be that Muhammad was able to bring many of the ideas of Christianity and Judaism, but these ideas helped to unify a fragmented Arab people, and not only did it unify them, but it gave them the energy that you can have through religious zeal, and that energy is what allowed them not only to unify in Arabia, and they're able to unify most of Arabia by the time of Muhammad's death, but within 100 years of his death, they're able to take over the entire Sassanid Empire and make major inroads into the Byzantine Empire, and so one argument might be, and I encourage you to argue with me, that they were unified, they had this missionary zeal, which perhaps was only seen in Christianity before Islam, and they were able to take advantage of conflict and discontent between the Byzantines and Persians in order to spread. Now another question is, do we see any patterns here? Are there any other examples in history of this happening? Well, the most comparable religion is Christianity, which is today larger than Islam, but Christianity, you have a long period between Jesus, who is the central figure of Christianity, who is the underlying spiritual figure, and when Christianity really spreads and really becomes an empire, and that really starts with Constantine roughly 300 years after the time of Jesus. What's interesting about the example in this video, the example of Islam, in terms of the religion, Muhammad plays a little bit of both of these roles. He is a spiritual figure.