The Mahdi ('The Guided One') is the Islamic Messiah or Saviour. According to Shiite Muslims, he is the 12th imam, a descendant of Ali, Muhammed's son-in-law. He went 'into hiding' in 874 and they expect him to return soon. Ahmadinejad, Iran's president, sees himself as the pioneer for the Mahdi. According to this doctrine the Mahdi will be a mighty political, military and religious leader in the last days.