The general belief at the time was that the purpose of the meeting was for the Ansar to decide on a new leader of the Muslim community among themselves, with the intentional exclusion of the Muhajirun (migrants from Mecca), though this has later become the subject of debate. Nevertheless, Abu Bakr and Umar, both prominent companions of Muhammad, upon learning of the meeting became concerned of a potential coup and hastened to the gathering. Upon arriving, Abu Bakr addressed the assembled men with a warning that an attempt to elect a leader outside of Muhammad's own tribe, the Quraysh, would likely result in dissension as only they can command the necessary respect among the community. He then took Umar and another companion, Abu Ubaidah ibn al-Jarrah, by the hand and offered them to the Ansar as potential choices. He was countered with the suggestion that the Quraysh and the Ansar choose a leader each from among themselves, who would then rule jointly. The group grew heated upon hearing this proposal and began to argue amongst themselves. Umar hastily took Abu Bakr's hand and swore his own allegiance to the latter, an example followed by the gathered men. Abu Bakr was near-universally accepted as head of the Muslim community (under the title of caliph) as a result of Saqifah, though he did face contention as a result of the rushed nature of the event. Several companions, most prominent among them being Ali ibn Abi Talib, initially refused to acknowledge his authority. Ali may have been reasonably expected to assume leadership, being both cousin and son-in-law to Muhammad. The theologian Ibrahim al-Nakha'i stated that Ali also had support among the Ansar for his succession, explained by the genealogical links he shared with them. Whether his candidacy for the succession was raised during Saqifah is unknown, though it is not unlikely. Abu Bakr later sent Umar to confront Ali to gain his allegiance, resulting in an altercation which may have involved violence. However, after six months the group made peace with Abu Bakr and Ali offered him his fealty. Rāshidun Caliphs Abu Bakr nominated Umar as his successor on his deathbed. Umar, the second caliph, was killed by a Persian slave called Abu Lu'lu'a Firuz. His successor, Uthman, was elected by a council of electors (majlis). Uthman was killed by members of a disaffected group. Ali then took control but was not universally