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-Nakhai 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.