The Twelfth Imam "Imam Mehdi (AS)"
First Heavenly concealment: 8th of Rabi-ul-Awwal, 260 A.H.
Final Heavenly concealment: 10th of Shawwal, 328 A.H.
There existed a good deal of harmony and uniformity between the aspects pertaining to the births of Prophet Muhammad, the last Apostle of Allah and Imam Mehdi, the last Apostolical Imam. Just as the coming of the Holy Prophet was prophesised well in advance by the preceeding Prophets similarly the impending news of the gracious birth of Imam al-Mehdi was foretold by the Holy Prophet.
Innumerable traditions in this context, quoted right from The Holy Prophet from the glowing contents of many books of Masanid, Sehan, and Akhbar and of Shia Scholars existed. Many Sunni scholars have accumulated these traditions in complete volumes also.
He was born on the 15th Shaban 255 A.H. in the city of Samarra. The momenton us and singluar aspects of his birth greatly resembled those under which the Prophet Musa was born. The birth of Hazart Musa had signalled the downfall and extinction of the empire of Pharoah, who had ordered the slaying of all the newly born children of Bani-Israel. The Abbaside kings were similarly apprehnesive of the continuous traditions of the Holy Prophet about the birth of Imam Mehdi, who was to bring about a curse to their (Abbaside) very empire. They were, therfore,
laying in ambush to discover the birth of the Imam and to put an end to his life. But the event of the Imam's birth was enveloped and shielded by the same Divine protection and miraculous phenomena which had makred the historical birth of Prophet Musa. His birth remained strictly confidential and his nursery shrouded in secrecy except to a few devotees.
The Imam's birth had coincided with the reign of al-Mutamad, the well-known Abbaside king. He, being aware of the prophecy of the twelfth Imam's birth occuring in his reign, was extremely worried and anxious to trace him out.
But on the death of Imam Hasan Askari, when he was informed about the Imam's funeral prayer having been conducted by his four year old son, his perplexity knew no bounds.
It struck his mind that this very boy must be the Imam, but he managed to hide his inner concern at the news of the existence of the young Imam. In order to get confirmation that the young Imam did in fact exist, he ordered the arrest of the Imam's mother, Janab-e-Nargis Khatoon.
MISC. Information on Imam Mehdi (AS)
In a tradition upon whose authenticity all Muslims agree, the Holy Prophet has said:
"Even if the entire duration of the world's existence has already been exhausted and only one day is left before Doomsday (Day of judgment), Allah will expand that day to such a length of time, as to accommodate the kingdom of a person out of my Ahlul-Bayt who will be called by my name. He will then fill out the earth with peace and justice as it will have been full of injustice and tyranny before then."
Sunni Reference: Sahih Tirmidhi, V2, P86, V9, P74-75 (There are many more.)
The context of the above precious tradition informs the golden divine promises will take place, sooner or later, one way or another, as mentioned in most of the Shi'ite and Sunnit sources.
In a tradition the Holy Prophet said to the Commander of believers, Ali, that: