Birth in Madinah
The eleventh Imam, Hasan b. Ali (a), was born in Madinah on 8 Rabi al-Thani 232 AH (some sources say the 10th). He was two or three when the caliph al-Mutawakkil ordered his father Imam al-Hadi (a) to Samarra, and he grew up in that garrison city under the eyes of the Abbasid court. The Shia call him al-Askari after the military quarter where the family was made to live.
Imamate
He became Imam in 254 AH at twenty-two. The caliphs imprisoned him more than once and had him watched constantly; even so he taught, corresponded widely, and appointed representatives through whom the community's questions and dues reached him. Hadith on Qur'anic interpretation, law, belief and supplication has come down from him, and Shia sources record the respect that scholars of Samarra had for his learning and bearing.
The father of the Awaited Imam
His son Muhammad (aj), the twelfth Imam, was born in Samarra in 255 AH, and it was Imam al-Askari (a) who presented the child to trusted followers so that the succession would be known. He was martyred by poison in 260 AH at twenty-eight and is buried beside his father in the Askariyyayn shrine.
Written for Shia Online Community. Dates and facts are checked against the references listed under Research & books; where the tradition records more than one date, all are given.