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. However, Ali’s future looked bleak at best. Ever since the dispute between Ali and Abu Bakr over the succession of Muhammad, which we discussed in Part 1, Ali had gained a fiercely loyal following. And despite Ali’s allegiance and loyalty to the first three Caliphs, a large group of Muslims still considered Ali as the only chosen and legitimate successor of Muhammad. According to Shia scholars, during the rule of the previous Caliphs, Ali’s family was harassed, a portion of their property was seized, and one instance even resulted in the miscarriage and death of his wife Fatima. However, Sunni scholars say that the allegations regarding the seized property were made-up and that the miscarriage and death of Fatima was an accident. What we know for certain is that, despite everything, Ali remained a strong supporter of unity amongst Muslims and continued to advise the Caliphs on a variety of political and religious subjects. For example, Ali advised Caliph Umar to set the First Hijra, the migration of Muhammad from Mecca to Medina, as the beginning of the Islamic lunar calendar. In his spare time, Ali held sermons and lectures. Over the years, he gained more and more followers, until eventually they became known as the Party of Ali, or the Partisans for short, which in Arabic translates to the Shiites. The Partisans had proclaimed their leader as the Imam. If the mainstream Sunni Muslim community had the Caliph, then the Shiites had the Imam. Therefore, the meaning of Imam is different for Sunni and Shia Muslims. Aside from this difference of titles, there were no cultural or religious differences between Muslims at the time, and there were no sects, cults or branches. More importantly, there was no schism - at least, not in the beginning or in the open.