To the Shiites he is a martyr, being believed to have been poisoned by Mamun.
The unfortunate fanatics were hunted down and massacred to the last man, and thereby the ties that bound the Abbasids to the ultra-Shiites were severed.
' Abul Hassan Ali, al Reza, commonly known as Imam Reza, the eighth imam of the Shiites, a son of Musa al Kazim, the seventh imam, was the leader from whom the party of the Alids (Shiites) had such hopes under the caliphate of Mamun.
The hidden imam of the common Shiites is, however, the twelfth imam, Mahommed Abu`l-Qasim, who disappeared mysteriously in 879.
1420, and is held in great veneration by all Mussulmans, and especially by Shiites, because it is supposed to be the tomb of Ali, the son-in-law of Mahomet.