In the previous three episodes of the History of Islam, we described the first three Caliphs and their characteristics. We also discussed their most notable accomplishments and the ways in which they ruled the Caliphate. Abu Bakr, the wise community leader and the founder of the Caliphate, had died from a fever. Umar, the military thinker and the founder of Islamic jurisprudence, was stabbed in the stomach by a mentally disturbed Sassanid slave. And Uthman, the merchant, and the builder, was beaten to death in his study room by fellow Muslims. It was then Ali’s turn as Caliph, making him the fourth to take the title.