The people who believed in this and Ali as the first successor became the Shias. On the other hand, some Sunnis believe that the Prophet explicitly chose Abu Bakr, his closest friend, advisor, and father-in-law, to lead the community, while others believe that he did not get a chance to choose any leader before his death. Nonetheless, Abu Bakr was unanimously elected the first Caliph of the Muslim community because he maintained order in the Muslim community after the death of the Prophet (Brown).
"Abu Bakr thus established by precedent the principle that there could be only one legitimate leader of the Muslims at one time " (Brown 117). Abu Bakr chose Umar ibn al-Khattab as his successor before his death to avoid another repeat of the past. Umar ibn al-Khattab was succeeded by Uthman ibn Affan, who was succeeded by Ali ibn Abu Talib. These four Caliphs are known as the Khulafa Rashidun or the Rightly Guided Caliphs. According to Sunnis, these are the four Caliphs that acted the closet to the sunnah of the Prophet (Brown). Even though these Caliphs lead the community and followed the sunnah, Sunnis do not believe that they are superior to other human beings. They believe that the Caliphs are normal human beings that can error or sin. It should be noted that Ali ibn Abu Talib did not become a Caliph until the fall of his three preceding Caliphs. The Shias have a completely different view on the leaders succeeding the Prophet. They argue that "Ali deserved the post in the very beginning and that the three preceding Caliphs were ˜usurpers' who denied him his rightful place " (Sinha 1). The Shias go to such extent as to " recite ˜Tavarra' in which they curse Ali's three predecessors, Abu-Bakr, Usman and Umar " (Sinha 1). This led to the start of a new leadership system for the Shia. .
Instead of abiding by the rule of the Caliphate, the Shias comply with the guidance of the Imamate.