But the community did need a political leader, a caliph, and the first caliph was Abu Bakr, Muhammad's father-in-law, who was not without his opponents. Many people wanted Ali, Muhammad's son-in-law, to lead the community, and although he did become the fourth caliph, that initial disagreement, to radically oversimplify because we only have ten minutes, began the divide between the two major sects of Islam, Sunni and Shia. And even today, Sunni Muslims believe Abu Bakr was rightly elected the first caliph, and Shia Muslims believe it should have been Ali. To Sunnis, the first four caliphs, Abu Bakr, Umar, Uthman, and Ali, are known as the rightly guided caliphs, and many of the conservative movements in the Islamic world today are all about trying to restore the Islamic world to those glory days, which, like most glory days, were not unambiguously glorious. Abu Bakr stabilized the community after Muhammad's death and began the process of recording the Quran in writing, and started the military campaigns against the Byzantine and Sasanian empires that, within 116 years, would allow the Islamic empire to go from this to this. His successor, Umar, was both an uncommonly good general and a brilliant administrator, but like so many other great men, he proved terrible at avoiding assassination, which led to the caliphate of Uthman, who standardized the Quran and continued both his predecessor's tradition of conquest and his predecessor's tradition of getting assassinated. Then Ali finally got his turn as caliph, but his ascension was very controversial and it ultimately led to a civil war, which eventually led to the emergence of Uthman's tribe, the Umayyads, as the dynasty that would rule over an ever-expanding Islamic empire for more than a hundred years.