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 (3rd vol., p. 2232) refers to his son, al-Mahdi under the name of Ibn al-Basri (the son of Basra), emphasising the connection of Radi Abdullah with southern Mesopotamia and the adjoining province of Khuzistan.
The Abbasid caliph al-Mutasim (218-227/833-842) was followed in succession by al-Wasik (227-232/842-847), al-Mutawakkil (232-247/847- 861), al-Muntasir (247-248/861-862), al-Mustain (248-252/862-866), al-Mutaz (252-255/866-869), al-Muhtadi (255-256/869-870) and al- Mutamid (256-279/870-892).
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.
Radi Abdullah was an erudite scholar and is celebrated to have epitomised 'Ikhwan as-Safa' into an instructive synopsis (al-jamia). Its full name was 'ar-Risalat al-Jamia' (the comprehensive espistle). It served as a substitute for the Epistle of 'Ikhwan as-Safa' and was 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).
It must be known that the monograph of 'ar-Risalat al-Jamia' was awarded the first Howard Bliss Prize by the American University of Beirut in 1929, and was subsequently published serially in the Journal of that institution, vide 'al-Kulliyat' (vol. xvii, 1930-1).
He was born in 204/828 and had joined the Ismaili mission at youth. He conducted his activities 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 Radi Abdullah promoted him to the rank of hujjat. He was known in Salamia as Ahmad al-Hakim, and died in 275/888. He was a man of great ability and is credited with having surveyed the above regions for forthcoming mission works.
Radi Abdullah had dispatched his dais in all directions, the most acclaimed among them was Abul Qassim Hasan bin Farah bin Hawshab, generally known by the epithet, Mansur al-Yamen (the victorious one of the Yamen). Ibn Hawshab was originally a Twelver, and is said to have spent most of time in a secluded spot on the bank of Euphrates. In such state, he is reported to have met Radi Abdullah and discoursed with him on religion. Imam left him after promising to see him again. Ibn Hawshab was impressed by his chance meeting with the Imam, and was eager to further meeting. After an anxious wait for several days, the Imam did not appear again, thus he became restless and began to search him. Despite his frantic efforts to locate the Imam's whereabouts, he could not trace him. After sometimes, he accidently met the Imam's deputy, and through him, Ibn Hawshab eventually succeeded in reaching the Imam's presence. Radi Abdullah answered his queries to his satisfaction and assuaged his doubts, and at length he espoused Ismailism. Radi Abdullah imparted him the knowledge of Islamic creed, tenets and esoterism.
When the Imam found that Ibn Hawshab was firmly grounded in Ismaili faith and groomed enough for the responsibility of its promulgation, he jointly entrusted him and his colleague, Ibn Fazal, with the task of Ismaili mission in Yamen. Before they set off on their venture, Radi Abdullah summoned them in a private audience and urged to respect each other, and avoid any sort of religious difference. He also entrusted Ibn Hawshab with a voluminous tome which comprehensively dwelled upon the exoteric and esoteric aspects of Ismaili faith. Thus, being equipped with verbal as well as written guidances, both of them set forth on their mission to Yamen in 266/880. Mecca was their first destination, and accosted the pilgrim caravan from Yamen. They proceeded at last to Yamen, and after reaching, both of them separated. Ibn Hawshab headed towards the southern region, and focused his mind on the village of Adanla'a, thickly populated by the Shiites. He married to a local woman and settled down in Adanla'a under strict taqiya. He succeeded to convert the inhabitants. When he found the time appropriate to reveal his identity, he discreetly started his mission, inviting the people to the Ismaili fold and accepting oath of allegiance on behalf of Radi Abdullah and his successor. On other side, Ibn Fazal also followed similar tract, and succeeded in winning the sympathy and adherence of the people of Saroyafoa.
Ibn Hawshab had managed to take possession of a stronghold constructed on a hillock and made it his headquarters. He arranged military training for his followers. He also took possession of Jabal al-Jusaysah and Jabal al-Maswar. Ibn Hawshab however assured the people that his campaigns were neither after booty nor personal glory, but these were meant to promulgate true Islamic message through Ismailism. Finally, he 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 dais to the farthest corners. Thus, Yamen became a vital zone and an important hub of Ismaili dawa. In the time of Radi Abdullah, Abu Abdullah al-Shi'i had embraced Ismailism, who was sent to Yamen for further training. Ibn Hawshab was loyal to the Imam till his last breath and died in 302/914. While reading his biography, we will greatly move the streak of intellectual honesty which ran through his very nature.
Abdullah bin Maymun (d. 260/874) is reported to have also sent a dai called Khalaf al-Hallaj, the cotton-dresser to Ray in about the middle of the third century with the instructions: 'Go to Ray, because there are many Shias in Ray, Aba, Qumm, Kashan and the provinces of Tabaristan and Mazandaran, who will listen to your call.' Khalaf went to the neighbourhood of Ray and resided in the district of Fashafuya, in a village called Kulin. He examined the local situation and started his secret mission. His secret activities however attracted attention, therefore he moved to nearby city of Ray, where he died. He is remembered as the founder of Ismaili dawa in Iran, and the converted people locally became known as Khalafiyya. He was succeeded by his son Ahmad, whose chief disciple was Ghiyath from the village of Kulin.
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 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.' (vide 'Tarikh', Karachi, 1966, 5th vol., p. 93).
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 remarkably marks the termination of dawr-i satr (concealment period) in the Ismaili history.
It is worth mentioning that the most important aspect of the Ismailism, which deserves serious treatment is to keep everything secret under the garb of taqiya connected with their faith, tending their enemies to contrived baseless stories and myths against them. The veiled period (dawr-i satr) thus became benigh climate for them to cultivate different wrong genealogies of the Imams. Thus, the ancestry of the Fatimids has confounded the students of history due to divergent accounts given by the historians, which had been developed round the persons of the 'hidden Imams' (aima'i masturin) during concealment period. The widespread Abbasid propaganda, the derogatory attitude of Sunnite and Shiite authors make difficult to decide one way or the other about the legitimacy of their claim. In the light of the Fatimid policy, we are inclined to believe that the Fatimids deliberately seem to have avoided discussing the matter of their ancestry. It emerges from this a safe conclusion that it was a preconceived plan of the Fatimids to keep their genealogy a top secret, owing to the intricate and dark passages it passed through and due to contradictions involved in the adoption of assumed names by the hidden Imams.
The variety of lineages suggested by the writers amounted to several hundreds, and the lineage between Wafi Ahmad and Radi Abdullah alone has been altered in no less than fifty ways. Since the hidden Imams had assumed different names in various regions to outsiders, in order to evade the vigilance of the Abbasids, the historians derived their informations on hearsay. The Ismaili Imams of that period were too cautious to disclose their true names; instead they assumed names, other than their owns and used for themselves the names of their dais. The hidden Imams, for the most part, could not pass the settled lives in specific places, but were known by names other than their own, sometimes by names of their dais and hujjats as a precautionary measure designed to ward off the danger of their persons being discovered.
The absence of detailed biographies of the three hidden Imams is also the result of their having lived in strict disguise. This seems quite probable, if one realizes the situation very seriously. What in fact would the popular memory preserve about the Imams when these were living ostensibly as local merchants, carrying on their business, associating with friends, directing their followers through secret agency of mission, marrying, educating their children, etc. The memory of these traditions is very meagre, retaining only reminiscences of the most important names and events. Similarly, the Ismaili dais also disguised as pious merchants of slightly lower standing, also left behind very trivial traces. Thus the leaving of any trace of their activities in writing was obviously avoided as much as possible. W.Ivanow writes in 'The Rise of the Fatimids' (Calcutta, 1942, pp. 43-44) that, 'Thus the long blank period in the story of the Imams, living in such conditions, cannot reasonably be taken as valid proof of the falsity of their claims to continuous succession from their original ancestor, Ismail b. Jafar.'
Even though the period of concealment and fear of the Abbasids were no longer in existence, the Fatimids were insistent not to divulge the names of their earlier three hidden Imams, the link between Imam al-Mahdi and Imam Muhammad bin Ismail. It seems quite possible that these Imams had assumed names for more than one time, and hid their true names, and were too complicated to be clarified. The followers also seem to have given much priority on the Imam of the time, descending from Muhammad bin Ismail. This secrecy however led too much confusion and made it too hard to locate the real names of the hidden Imams. It is also a striking feature that these three hidden Imams are not mentioned by the early renowned Ismaili scholars, viz. Abu Hatim ar-Razi (d. 322/934), Qadi Noman (d. 363/974), Jafar bin Mansur al-Yamen (d. 365/975) and other authors of 4th/10th century.
Commenting the aggressive attitude of the historians, Ivanow writes in 'The Rise of the Fatimids' (Calcutta, 1942, p. 29) that, 'With their predominantly hostile tendency, each author vie with the others in inventing something more humiliating and scandalous for the dynasty.' The diversity of the names of the three hidden Imams can be judged from the following list of some special surname and epithet, whose implications were intelligible only to the trusted followers, indicating a causative factor of the contradictions in the sources:
ABDULLAH : Radi, Ahmad, Abu Muhammad, al-Wafi AHMAD : Wafi, Muhammad, Abul Hussain, at-Taqi. HUSSAIN : Muhammad, Taqi, Ahmad, Abu Abdullah, az-Zaki, al-Muqtada al-Hadi, ar-Radi.
The fact about the Imams assuming the above code names in one or more times can be derived from the letter of Imam al-Muizz (341-365/953-975), which he routed in 354/965 to his dai in Sind, named Jaylam bin Shayban, which is preserved in the 5th volume of 'Uyun'l-Akhbar' by Idris Imaduddin. According to 'Expose de la Religion des Druzes' (Paris, 1838, p. 252) by de Sacy, 'These men (hidden Imams) obliged to seek concealment, took sometimes one name and sometimes another, in order to shelter from the pursuit of their enemies.' John Nicholson also writes in 'Establishment of the Fatemide Dynasty in Northern Africa' (1840, p. 12) that, 'They themselves have taken different names at different times in order to elude discovery.'
According to 'an-Naqdu'l-Khafi' by Hamza (cf. 'Expose de la Religion des Druzes' by Silverstre de Sacy, Paris, 1838, p. 74) that the Fatimid Caliph, al-Muizz had once said: 'I am the seventh in the second heptad.' As is well known, al-Muizz was the 14th Imam in the second heptad. The Imams of the first heptad were seven and the seventh one was Muhammad bin Ismail, and the Imams followed after him were also seven to make al-Muizz as the 14th Imam. Hence, the 13th Imam was al-Mansur, the 12th was al-Qaim and 11th was al-Mahdi. It therefore emerges conclusively that there must have been three Imams between al-Mahdi and Muhammad bin Ismail, whose names were Abdullah (Wafi Ahmad), Ahmad (Taqi Muhammad) and Hussain (Radi Abdullah) from 8th to 10th in the sequence. W. Ivanow writes in 'Ismailis and Qarmatians' (JBBRAS, Bombay, 1940, p. 74) that, 'Being the fourth Fatimid Caliph, al-Muizz was the seventh Imam after Muhammad bin Ismail. Thus this formally rejects the theory of the Fatimids descending from Abdullah bin Maymun.'
The statement of al-Muizz however does not contain the explicit names of the 'three hidden Imams', but before that, it is known that al-Mahdi had sent a letter in Yamen, which reached there after his arrival in Mahdiya in 308/921. Jafar bin Mansur al-Yamen (d. 365/975) had quoted the letter in his 'al-Fara'id wa Hudud ad-Din' (pp. 13-19), wherein the names of the three hidden Imams have been mentioned, viz. Abdullah, Ahmad and Muhammad. Dr. Sami Nasib Makarem writes in 'The Hidden Imams of the Ismailis' (al-Abhath, 21, 1969, p. 24) in this context that, 'If al-Mahdi's letter is authentic, it is one of the oldest documents that have come to light until now, and, consequently a most reliable document, especially because it was written by the Caliph al-Mahdi himself.'
Among the later Ismaili historians, Ahmad bin Muhammad an-Naysaburi, the author of 'Istitaru'l-Imam', compiled under Imam al-Aziz (365-386/975-996) seems first to have mentioned the names of the three hidden Imams. Later on, such references appear in the works of Hamiduddin Kirmani (d. 408/1017), in his 'Tanbihu'l-Hadi wa'l-Mustahdi' and 'ar-Risalat al-Wa'iza'. Idris Imaduddin (d. 872/1468) in 'Uyun'l-Akhbar' and Hasan bin Nuh Broachi (d. 939/1533) in 'Kitabu'l Azhar', had also advanced brief biographies of the three hidden Imams.
In sum, R. Strothmann writes in 'Gnosis-Texte der Ismailiten' (Gottingen, 1943, p. 59) that, 'The three Imams followed by Muhammad bin Ismail were in concealment: Abdullah al-Rida, Ahmad al-Wafi and Hussain al-Taqi, and finally the beginning of the Fatimid dynasty with al-Mahdi.'