Tarikh Islam

Ghadir is an undenaiable historical fact in Islam and will never be forgotten. Thus, Imam Ali (A), from the very first days of Abu Bakr's caliphate would refer and attest to Ghadir Khomm as the evidence for his right to the caliphate and the rightful successor of the prophet Muhammad and the leader of the Muslim community, in addition to enumerating his own merits which would cause him to deserve being a caliph. Imam Ali's mentioning the important event of Ghadir and his referring to it repeatedly was, in effect, a challenge to the usurpers of the caliphate. He did so both in facing with Abu Bakr and, afterwards, during the reign of the other Caliphs; and even on his accession to caliphate, he would refer and attest to Ghadir Khumm at which the Prophet made an announcement to the pilgrims who accompanied him and chose and appointed him (Imam Ali) as his rightful successor after him