Who is the Mahdi of Islam? According to both Sunni and Shi'i Muslims, the "guided one" will rise during the end times to conquer all nations. With Jesus Christ, he will bring an end to aggression and injustice, and will establish the Kingdom of God on earth. However, Sunnis and Shi'is disagree about the identity of the Mahdi. According to Shi'is, the Mahdi - an extraordinary human being who will perform extraordinary miracles - is Muhammad b. al-Hasan al-Husayni. He was born over a thousand years ago, and is still alive on this earth, but living in occultation, and will reappear during the end times. For Sunnis, however, the Mahdi will be an ordinary and mediocre man by the name of Muhammad b. 'Abd Allah al-Hasani. In "Imam al-Mahdi: The Twelfth Khalifah in the Sahih Sunni Ahadith", author Toyib Olawuyi argues that the identification of the awaited Mahdi with Muhammad b. 'Abd Allah al-Hasani is not established in any reliable Sunni or Shi'i hadith, but is based on only a few unreliable Sunni reports. By contrast, Olawuyi demonstrates, Muhammad b. al-Hasan al-Husayni is confirmed as the Mahdi in both authentic and authoritative Shi'i and Sunni sources. "Imam al-Mahdi" is a carefully balanced work of scholarship that will both inform and challenge the views of many Muslims and non-Muslims alike.