Mahdi is the name of the last of the 12 Imams. The first Imam was Ali, son–in–law of Mohammed. According to Islam and in particular the Shiites, Mahdi comes at the time of the Last Judgement to save the world. The return of Mahdi constitutes the most frequent prophetic theme of the Imams. Al–Kultani and al–Nu’mani consecrated an entire chapter and Ibn Babyne passed down in 13 chapters the predictions of the Prophet, Fatima and the 11 Imams on the subject of the Twelfth Imam.
The obscured presence of Mahdi totally dominates the religious conscience of Imamism during the period of his disappearance until the return of the awaited Saviour.