Abd Allah al-Radi
Abu ʿAlī al-Ḥusayn ibn Aḥmad ibn ʿAbd Allāh ibn Muḥammad ibn Ismāʿīl, also known as al-Zakī, al-Raḍī and al-Muqtadā al-Hādī, was a descendant of the Islamic prophet Muhammad and the tenth of the Isma'ili Imams, succeeding his father, Muhammad al-Taqi. Before his death in 881, he entrusted the care of his son and successor, Abd Allah al-Mahdi who was then around 8 years old to his full brother, Sa'id al-Khayr, also known as Abu'l-Shalaghlagh.
Historical background
With the death of Ja'far al-Sadiq in 765, Isma'il and Muhammad, the gravity of the persecution of Isma'ili Imams and their supporters by the Abbasids had considerably increased. The Isma'ili Imams were compelled to hide, therefore, the first dawr al-satr came into force from 765 to 909. During this period, the Imams were known as al-a'imma al-masturin. The Imam's identity was hidden to protect the Imam from being persecuted by the Abbasids and the community continued to operate under the authority of Muhammad ibn Isma'il. According to later tradition, these Imams were Abd Allah, Ahmad and al-Husayn. Among the later Isma'ili historians, Ahmad ibn Ibrahim al-Naysaburi, the author of Istitār al-Imām'', compiled under the Fatimid Imam, Caliph al-Aziz Billah, seems to be first historian to mention the names of the three 'hidden' Imams.A modern historian of the Fatimid period, Shainool Jiwa, explains that during dawr al-satr Ismaili doctrine had spread as far as from Yemen to Ifriqiya, with its most prominent adherents being the Kutama Berbers of North Africa.
Life
Husayn ibn Ahmad was born in 825 and assumed the Imamate in 840. His hujjat was Ahmad, surnamed al-Hakim, a descendant of Husayn ibn Ali, to whom Abd Allah ibn Maymun al-Qaddah handed over his position. Al-Radi's home was in Salamiyah, where he lived among the Hashimites and acted as if he was one of them. He gave presents to the local governors and was lavish with hospitality. He is said to have granted allowances from his wealth to the poor and disabled persons in Salamiyah without discrimination between the Isma'ilis and non-Isma'ilis. His father Muhammad al-Taqi is remembered for his Encyclopedia of the Brethren of Purity, which his son is said to have summarised in his Jāmiʿat al-Jāmiʿa. Al-Radi is remembered for his daʿwah or proselytising.Al-Radi travelled to Kufa, on pilgrimage to the tombs of Ali ibn Abi Talib and his son, Husayn. While there he met Abu al-Qasim ibn Hasan ibn Farah ibn Hawshab, who was of the Twelvers and was associated with Hasan al-Askari. He also met Ali ibn al-Fadl al-Jayshani. He sent both men to Yemen to establish the way of the Isma'iliyya there. They reached Yemen, and conquered Sanaa, the capital of Yemen, and exiled the ruling tribe of Banu Laydir, and established Isma'ili authority in Yemen.Al-Radi died in 881 at Salamiyah while he was travelling in the vicinity. Before his death he appointed as his trustee his brother, Sa'id al-Khayr, also known as Abu'l-Shalaghlagh. He also made Abu'l-Shalaghlagh the guardian of his son, al-Mahdi. It is stated in the Istitār al-Imām that the guardian, Abu'l-Shalaghlagh, the 'acting Imam', tried to usurp the Imamate for his own line, appointing one after another his sons successively as his heir, but that all of his sons died.