He is the promised savior, who will rise one day and fill the earth with peace and justice. Imam al-Mahdi (a) has been in occultation from the early years of his life. Shi'as regard him as the Imam of the present age. Among his well-known titles are Imam al-Zaman (the Imam of the time) and Wali l-'Asr (the guardian of the age).
Imam al-Mahdi (a) became the Imam after the demise of his father Imam al-Hasan al-'Askari (a) in the year 260/874, when he was five. From that time until the year 329/940, he was in contact with his followers through his Four Deputies. After that, his Major Occultation started, in which period the direct guidance and leadership of the Shi'a community rests with religious scholars.
There are many hadiths transmitted from the Imams (a) about Imam al-Mahdi (a), his life, his Occultation, and his government, and many collections of such hadiths have been written. In addition to hadith collections, many works have been published about Imam al-Mahdi (a).
Every year, on Sha'ban 15, Shi'as celebrate the Imam's birth, marking one of the greatest Shi'i festivals.
The possibility of meeting the Imam (a) during his Major Occultation, when and how he reappears, and the incidents related to his reappearance are some of the popular discussions among Shi'as.
Lineage and Birth
In Shi'a hadiths, the Twelfth Imam (a) is referred to by names such as Muhammad, Ahmad, and 'Abd Allah. However, among the Shi'as he is most famously referred to as al-Mahdi which is one of his titles.
According to a number of hadiths, he is the Prophet (s)'s namesake. In some hadiths and written Shiite sources, such as al-Kafi and Kamal al-din, his name is written with separate letters as "م ح م د" (M H M D). This is in accordance with hadiths forbidding any mention of Imam al-Mahdi's (a) name.
Place of Birth
Historians who talked about the issue agree that Imam al-Zaman (a) was born in the house of his father, Imam al-Hasan al-'Askari (a), in Samarra. The house is now part of the shrine of Imam al-Hadi (a) and Imam al-'Askari (a). Imam al-Hadi (a) and Imam al-'Askari (a) were summoned to Samarra, the center of the Abbasid Caliphate, years before the birth of Imam al-Zaman (a) and lived there until they were martyred.
Secret Birth
Abbasid caliphs knew from the hadiths by the Prophet (s) and the Imams (a) that the Twelfth Imam was al-Mahdi, and thus, they assigned some guards to monitor Imam al-Hasan al-'Askari (a) and his house. According to historians, al-Mu'tamid al-'Abbasi had ordered the midwives to drop by sadat's houses, especially the house of Imam al-Hasan al-'Askari (a), search inside the house, learn about his wife, and report him about it.The birth of Imam al-Zaman (a) was hidden from people.