The Mahdi (Arabic: مهدي
transliterated: Mihdī, also Mehdi "Guided One"), in Islamic
eschatology, is the prophesied redeemer of Islam, who will
change the world into a perfect Islamic society before Yaum al-Qiyamah
(literally "Day of the Resurrection").
The exact nature of the Mahdi differs according to Sunni and
Shia Muslims.