What happened to Islam after the death of the Prophet Muhammad? Well, there were succession crises, assassinations, conquests, and rebellions. This time of expansion and turmoil was lead by the Rashidun, or the "Rightly Guided" Caliphs. Men who personally knew the prophet, and are recognized by all Muslims as genuine successors to Muhammad. But short sighted mistakes would lead to the end of the Rashidun Caliphate, and the Birth of the Umayyad Caliphate.