The Problem of Succession
nArab victories for a time covered old tribal internal divisions. The murder of Uthman, the 3rd caliph, caused a succession struggle.
nMuhammad’s earliest followers supported Ali , but he was rejected by the Umayyads.
nIn the ensuing hostilities Ali won the advantage until at Siffin in 657 he accepted a plea for mediation.
nAli lost the support of his most radical adherents, and the Umayyads won the renewed hostilities.