“The Rightly-Guided One” (Arabic al-mahdī) in Islam is an attribute of the prophet and his first successors, the Caliphs, whose “right guidance” (Arabic al-hudā) by God was generally recognized by early Muslims. This consensus collapsed in the course of the rapid expansion of the Caliphate and in the deep conflicts of interest that came with the construction of state institutions and the distribution of profits from conquest. For a time, these…