Succession to Muhammad

A pivotal event took place in 632 at Ghadir Khumm, where the Islamic prophet Muhammad, shortly before his death, took Ali, his cousin and son-in-law, by the hand and delivered a speech in which he said "Whoever I am his mawla, then Ali is his mawla." The word mawla has several meanings depending on the context, including master, protector, ally, supporter, and one with authority. In Shia Islam, it is understood as Muhammad's formal designation of Ali as his successor. Sunni Islam also accepts that the event of Ghadir Khumm took place and that Muhammad made the statement about Ali. However, it does not interpret the statement as a designation of Ali as Muhammad's successor. Sunnis interpret the word mawla in this context as referring to a close associate, friend, supporter, or one deserving loyalty and affection. Therefore, they regard the declaration as a simple affirmation of Muhammad's esteem for Ali, minimizing the event’s importance.

When Muhammad died in the same year, his father-in-law Abu Bakr was chosen as his successor at Saqifah by a group of the prophet's companions, while Ali was attending to the prophet's funeral and was therefore absent from the gathering. Shia Muslims hold that Abu Bakr's appointment bypassed Ali's rightful claim to the succession, since Muhammad had already designated Ali as his successor at Ghadir Khumm. Sunni Muslims hold that Muhammad left the choice of his successor to the community, and therefore regard Abu Bakr's selection by companions as legitimate. The succession crisis became the initial cause of the division among Muslims that led to the emergence of the two main Islamic branches, Sunni and Shia. Ali was followed by a line of divinely appointed Imams from Muhammad's household. The largest denomination of Shia Islam, Twelver Shi'ism, recognizes the Twelve Imams as the divinely appointed leaders, beginning with Ali himself and ending with the Mahdi, who is believed to be in occultation and expected to return in the End Times to establish justice and will be assisted by Isa (Jesus).