Molana Hussain al Mastoor a.s.(225-268 AH / 840-881 AD)

Hussain bin Ahmad or Abu Abdullah, surnamed az-Zaki, known as Hussain ar-Radi, or Radi Abdullah (Servant of God who is satisfied and content), was born in 210/825 and assumed the Imamate in 225/840. He is also called Muhammad and al-Muqtada al-Hadi. His also kept his identity secret being represented by his hujjat, Ahmad, surnamed al-Hakim. Tabari (3:2232) refers to his son, al-Mahdi under the name of Ibn al-Basri (the son of Basra), emphasizing the connection of Imam Radi Abdullah with southern Mesopotamia and the adjoining province of Khuzistan.
 
Imam Radi Abdullah is celebrated in devoting time to complete the task of his father, his teachings and institutions. In his time, the faith of the Ismailis spread by leaps and bounds with galloping speed through out the length and breath of Arabia.
 
Imam Radi Abdullah was an erudite scholar and is celebrated to have epitomized Ikhwan as- Safa into an instructive synopsis (al-jamia). Its full name wasar-Risalat al-Jamia (comprehensive epistle). It served as a substitute for the Epistle of Ikhwan as-Safa, intended for private circulation among the more advanced members of the groups. The al-Jamia is the backbone of the Epistles, which was further summarized in Risalat al-Jamiat al-Jamia an al- Zubdah min Rasail Ikhwan as-Safa (the condensation of the comprehensive epistles, or the cream of the epistles of Ikhwan as-Safa).
 
Ahmad bin Abdullah bin Maymun was born in 204/828 and had joined the Ismaili mission at youth. He operated his mission in Iran and Iraq. His father had sent him with a deputation to make a survey in Yamen, where he collected the informations for the headquarters and also travelled as far as Bahrain. After his father’s death in 260/874, he returned to Salamia, where Imam Radi Abdullah promoted him to the rank of hujjat. He was known in Salamia as Ahmad al- Hakim, and died in 275/888.
 
Imam Radi Abdullah had dispatched his da’is in all directions, the most acclaimed among them was Ibn Hawshab. When the Imam found that Ibn Hawshab was firmly grounded in Ismaili faith and groomed enough for its promulgation, he entrusted him and his colleague, Ibn Fazal, with the task of Ismaili mission in Yamen. They reached Yamen, and conquered Sana’a, the capital of Yamen, and exiled the ruling tribe of Banu Laydir, and established Ismaili authority in Yamen. The Ismaili mission reached the apex of its influence in Yamen, from where Ibn Hawshab dispatched many da’is to the farthest corners. Thus, Yamen became a vital zone and an important hub of Ismaili mission.
 
Abu Abdullah al-Shi’i was hailed from Kufa, where he had been an inspector of weights and measures, and was also an ascetic of Shi’ite inclinations, having been converted along with his brother, Abul Abbas bin Ahmad to Ismailism by da’i Firuz. Realizing his potential, Imam Radi Abdullah sent him to Ibn Hawshab in Yamen for further training in Ismaili esoteric doctrines as well as affairs of the state. Abu Abdullah stayed in Yamen with Ibn Hawshab for a year.
 
Imam Radi Abdullah continued his peaceful living in Salamia, associating the local Hashimites. He also kept on good terms with the local governor. He seems to have been active in scholarly matters without a bearing in the politics. He was rolling in plenty; yet he contented himself with plain dress and simple food. He was humble in disposition and very hospitable. He is said to have granted allowances from his wealth to the poor and disabled persons in Salamia without discrimination between the Ismailis and non-Ismailis. Tradition has it that he was fond of horsing, shooting, hunting and archery, which had been also a favourite pastime of the Hashimites in Syria.
 
When Imam Radi Abdullah felt that the shadows of his death were closing upon him, he consigned the office of Imamate to his son, Muhammad al-Mahdi, saying, according to Ibn Khaldun that: "You are the promised Mahdi. You would take refuge in a remote land after my death, where you would have to submit to hard trials." (Tarikh, Karachi, 1966, 5:93).
 
Imam Radi Abdullah died in 268/881 at Salamia while he was travelling in the vicinity, appointing before his death as his trustee his own brother, Muhammad bin Ahmad, surnamed Sa’id al-Khayr as the guardian of his son, al-Mahdi. His death in 268/881 marked the termination of dawr-i satr(concealment period) in the Ismaili history.