Ishaq bin al-Abbas al-Farsi, the Abbasid governor of Ray privily professed Ismaili doctrines. Muhammad betrothed to Fatima, the daughter of Sarah, sister of Ishaq bin al-Abbas; who gave birth to a son, who was named Abdullah, also known as Wafi Ahmad. When the news of Muhammad bin Ismail's stay at Ray reached the ears of Harun ar-Rashid, he wrote to Ishaq bin al-Abbas, ordering to arrest Muhammad and send him to Baghdad. Upon receipt of caliph's letter, he showed it to the Imam and replied to the caliph that he found no trace of Muhammad, and would send as soon as he was arrested, and thus he tried to put the caliph off the scent. But the spies planted by Baghdad were vigilants and reported to the caliph that Muhammad bin Ismail not only was living at governor's house, but that he was directing his mission from there. Upon this, the caliph wrote another letter to Ishaq bin al-Abbas, impugning him to come in person with his forces if his orders were not obeyed forthwith. The governor however made his usual reply.
Meanwhile, the complaints about Ali bin Musa bin Mahan, the governor of Khorasan reached the point where Harun ar-Rashid could no longer ignore them. With the intention of deposing his governor and to make a search of the Ismaili Imam, Harun ar-Rashid adopted a militant stance. In 189/805, he marched towards Ray with a detachment of his army, and after searching for the Imam through a tracking party, ordered the arrest and torture of Ishaq bin al-Abbas. He however did not give away any clue of the whereabouts of the Imam. Ishaq died as a result of severe and cruel torture that was inflicted upon him, and was rigorously flogged till death. He did not waver and stood firm in spite of excruciating tortures. In spite of the gloomy situation, however, his faith remained unshakable.

Admittedly, it is learnt that after leaving Medina, Muhammad bin Ismail made his way towards Iran and Syria accompanied by Maymun al- Qaddah. The bitterest of the Abbasids' enmity was daily growing in intensity. Apprehending lest the enemies should resort to some violent measures against him, Muhammad assumed the name of Maymun al-Qaddah to elude discovery. Thus, the name Maymun al-Qaddah came to be used by two characters at one time. It was also resolved, if the real identity of the Imam be traced, Maymun al-Qaddah was to come forward as Muhammad bin Ismail to sacrifice his own life in order to protect the line of Imamate from extinction.
Henceforward, Muhammad bin Ismail had also a sobriquet of Maymun al-Qaddah to conceal his identity. In fact, Maymun al-Qaddah had a son, named Abdullah (d. 260/874), while Muhammad bin Ismail had also a son at the same time, called Abdullah (d. 212/828), surnamed al-Wafi Ahmad. With the passage of time, Muhammad became known as Maymun al-Qaddah in the places he resided, while Maymun al-Qaddah was treated as Muhammad bin Ismail in the regions he propagated Ismailism. Abdullah, the son of Maymun al-Qaddah was consequently considered as the son of Muhammad bin Ismail in the regions where the Imam had assumed the title of al-Qaddah. It therefore gave rise to the contrivance of a story that Abdullah (al-Wafi Ahmad) was the son of Maymun al-Qaddah on one hand, and Abdullah (bin Maymun al-Qaddah) was the son of Muhammad bin Ismail on other. Later on, it became an instrument for the anti-Fatimid propagandists, notably Ibn Razzam to join the lineage of the Fatimid Imams with that of Abdullah bin Maymun al-Qaddah instead of Abdullah (al-Wafi Ahmad) bin Muhammad bin Ismail. This is known as Qaddahid theory and became a weapon of the later Abbasids to discredit the Fatimid origin in 401/1010.

In the face of these facts, the Ismaili Imams had assumed the titles of the dais in one or more time during the veiled period, which is also sounded expressly in the letter of the Fatimid Imam al-Muizz (341-365/953-975), written in 354/965, addressing to his dai in Sind, called Jaylam bin Shayban. This important letter is well preserved by Idris Imaduddin (d. 872/1468) in the 5th volume of 'Uyun'l-Akhbar'(comp. 842/1438). It reads:- '.... These people have arbitrarily limited (the period of Imamate) by (the death of) Muhammad bin Ismail; and when he died, they said about him all what was said by them. They (also) thought that he entrusted the Imamate to some one who was not his son. And that his successor (similarly) entrusted the Imamate (to his own) successors, whose number has (also) reached the number of seven. They thought that the first (of these pseudo-Imams) was Abdullah bin Maymun al-Qaddah. All this is preached in order to prove their theory that there was no Imam after him (i.e., Muhammad bin Ismail), and that those who succeeded him were ordinary people. Thus they have cut what God ordered to be continuing (the line of Imams), opposing the command of God, given in the Koran (47:27). '....and We have made a word to remain after him.' The cause of this requires explanation. When the preaching in favour of Muhammad bin Ismail has spread, the Abbasid usurpers tried to lay their hands upon him, i.e. the person whose rights were claimed. Therefore (he and other) Imams went into concealment. Their dais used to refer to them under allegorical names, in accordance with the principle of taqiya, alluding to what they possessed and what was appropriate to them. They used to say, for instance, that the Imam, the son of Muhammad bin Ismail was Abdullah. And this was true. And with regard to his being the son of Maymun al-Qaddah, it was true that he was the son of Maymunu'n naqibat, i.e. of the 'Divinely blessed with success in his affairs,' of al-Qaddah (the flint) 'striking the sparks of guidance', i.e. 'lighing the light of the Divine wisdom'. Similar allegorical expressions were applied also to other Imams after him, at their own orders and instructions given to their dais. When such allegorical expressions reached those who know nothing about their real implications, and only took them literally, as we mentioned above, they fell into an error, and made others err after them, straying from the straight path. But if they would only do what God has ordered them to do, rallying around the Imams, they surely would know those who were otherwise hidden from them. Just as you know them now. But the blind, who has no one to lead him, or a stick in his hand, falls into an abyss from which no one can save him. The self-conceited fall into sin and error. So beware of thinking that God ever abandons humanity to itself. No, He does not abandon them even for a moment, leaving them without an Imam from the descendants of the Prophet. And the Imams can come to their office only by the commandments relating to Imamate....'

In addition, Hatim bin Imran bin Zuhra (d. 498/1104) writes in his 'al-Usul wa'l-Ahkam' that, 'The dais used their own names as nick-names for the Imams in order to protect them from persecution; some people were misled by this to such a degree that they said that the Imam, descendant of Muhammad bin Ismail was Abdullah bin Maymun al-Qaddah.' According to Arif Tamir in 'al-Qaramita' (p. 87), 'When Muhammad bin Ismail fled from the east and established in Palmyra in Syria, the centers of his activities; he called himself Maymun al-Qaddah.' Syed Abid Ali Abid writes in 'Political Theory of the Shiites' (cf. 'A History of Muslim Philosophy', ed. by M.M. Sharif, Germany, 1963, 1st. vol., p. 740) that, 'As a matter of fact, as the latest research has established beyond any doubt, Maimun was the name adopted by Imam Muhammad when he went into concealment. In other words, during the period of concealment those who were in his confidence knew Imam Muhammad to be a Maimun.' Husayn F. al-Hamdani (1901-1962) writes in his 'On the Genealogy of Fatimid Caliphs'(Cairo, 1958, p. 18) that, 'It is likely that Muhammad b. Ismail, who did not, and could not, according to accounts, live a settled life at one place, went underground during his wanderings by assuming the name of Maymun.'

Before biding goodbye to his ancestral abode, Medina, Muhammad had secretly convened an assembly of his dais, inviting them from all the regions. When caliph Harun ar-Rashid came to know the secret assembly, he resolved to arrest Muhammad bin Ismail in Medina. In the meantime, Zubeda, the wife of Harun ar-Rashid and a secret follower of the Imam, managed to send her trusted servant towards the Imam in Medina, informing him the plan of the caliph. Thus, Muhammad bin Ismail had to make his footing out of Medina at once.

Tradition however has it that Muhammad first went to southern Iraq, where he acquired the epithet of al-maktum (veiled one), and then at Nishapur in disguise, where he lodged for some times. Nishapur was one of the most important of the four great cities of Khorasan. The word 'Nishapur' is derived from New-Shapur. In Armenian it is called Niu-Shapuh, then became Nishwpur, finally Nishapur. It is situated on the east side of a plain surrounded by hills. To the north and east of the town lies the ridge of Binalud-Kuh, which separates it from the valley of Mashhad and Tus. It was divided into 42 wards, 1 farsakh in length and breath. Muhammad afterwards proceeded towards Ray (the ancient Ragha), a town in Media, about 15 miles from Tehran. Ray was situated in the fertile zone which lies between the mountains and the desert. The Abbasids rebuilt and surrounded it by a ditch. Harun ar-Rashid was also born in Ray and used often to recall with pleasure his native town. In 195/810, caliph Mamun's general Tahir bin Hussain won a victory over caliph Amin's troops near Ray.

Ismail lived for the most part in Salamia, where he died after bequeathing the office of Imamate to his son Muhammad. According to 'al- Usul wa'l Ahakam' by Hatim bin Imran bin Zuhra (d. 498/1104) that, 'Ismail had sent his dais to all parts and ordered him (Muhammad) to administer the oath in his name according to the custom of all preceding Imams. When his death drew near, he appointed as his heir, his son Muhammad who showed great perfection.'
The predeseased tradition assigns Ismail's death in 145/762, but 'Dustur al-Munajjimin' (comp. 450/1056) places it in 152/769. According to the Ismaili tradition, Ismail died in 158/775, and was interred in Salamia. Besides Muhammad, he had a son called Ali, who was born in 130/748 and a daughter, Fatima.

Maymun al-Qaddah was born in Ahwaz in Iran. He belonged to the Makhzumi clan and was the mawla (freed slave) of Imam Muhammad Bakir and Imam Jafar Sadik. His surname 'al-Qaddah' is usually taken to mean 'oculist', which seems extremely doubtful. It is a word connected with al-qidah i.e., an ancient Arab play or a form of divination with the help of arrows. Tusi (d. 460/1068) in 'Tahdhibul Ahkam' while dealing with Maymun al-Qaddah, explains the word as 'a man who practises the game of qidah (yabra'ul qidah). Thus, he was a specialist in divination with the help of arrows.
Maymun al-Qaddah was a very pious man of ascetic life. Because of his close association and faithfulness, he was chosen for the task of stimulating the secret Ismaili mission, and became the primary architect in articulation of the Ismaili mission.

It also appears that the activities of Maymun al-Qaddah had been exaggerated by the Arabs because of being an Iranian. The derogations of his Arab enemies can be judged from their baseless propaganda that he and his son, Abdullah bin Maymun were against the Islamic tenets, and had planned to blow it up, and broadcast that the Ismailism was typically an Iranian. Silvestre de Sacy (1758-1838) therefore, is inclined to make his judgement curiously in his 'Expose de la Religion des Druzes' (Paris, 1838, p. 31) that the Ismaili doctrine is typically Iranian, and later E.G.Browne in 'A Literary History of Persia' (New York, 1902, 1st vol., p. 405) also advanced same views. Being influenced with the Arab propaganda, the orientalists adopted the theory that the Ismailis were of Iranian origin, which has been however falsified by W. Montgomery Watt, vide 'Islamic Philosophy and Theology' (Edinburgh, 1985, p. 126). This idea led the other scholars to theorize the Ismailism not merely an anti-Arab movement, but more so an anti-Islamic revolution; but the recent researches have ruled out such groundless propaganda.

Allegorical interpretation (tawil) of the Holy Koran was in vogue among the people of all walks of life, attempting the evolution of a religious philosophy. The Ismaili dais had purified the Islamic Shariah polluted by the ignorants. The draining off the adulterated tenets through the agency of tawil by Maymun al-Qaddah and his son was violently opposed and misinterpreted by the Arabs, who were basically against the philosophical approaches. Most of the historians tried to project Maymun al-Qaddah as an enemy of Islam, planning to destroy it from within by founding the Ismaili movement and evolving its doctrines in such a way as to present Zoroastrian or Manhchean teachings in the Islamic garb. These historians want us to believe that Maymun al-Qaddah had nothing but contempt for Islam and fierce hatred towards the Arabs and that they conceived the idea of a secret society which should be all things to all men, and which, by playing on the strongest passions and tempting the inmost weaknesses of human nature, should unite malcontents of every description in a conspiracy to overthrow the then existing Abbasid regime. These are fantastic allegations levelled with a calculated purpose to discredit the Ismailis in the eyes of orthodox Muslims. Many eminent orientalists like de Goeje, R.A. Nicholson, etc., have erred in taking this story from the prejudiced historians.

Evincing their utter ignorance, the philosophy was officially banned in the orthodox orbits, propagating that it was the tool used by the Ismaili dais to undermine Islam. Syed Abid Ali Abid writes in 'Political Theory of the Shiites' (cf. 'A History of Muslim Philosophy' ed. by M.M. Sharif, Germany, 1963, 1st. vol., p. 740) that, 'The orientalists - nay even such an erudite Iranian scholar as Muhammad Qazwini, the editor of 'Tarikh-i Jhangusha' by Ata Malik Juvaini - were misled by the voluminous Abbasid propaganda, hostile commentary of the orthodox Shiites, and the specious argument of those opposed to the Ismailites, into thinking that Maimun and his son Abd Allah were opposed to the tenets of Islam or were inspired by the hatred for the Arabs.' J.J. Saunders also advanced his doubts in this context, vide 'A History of Medieval Islam' (London, 1965, p. 128). Besides, Maymun al-Qaddah is shown as a real founder of Ismailism, which is starkly a fabrication, and it was apparently a 'brain-wave' on the part of Ibn al-Razzam, whose historical character is yet doubtful.

Maymun al-Qaddah was canonised in the rank of hijab (screen), whose function was in addition to screen the real Imam from his enemies, and was thus the hijab of Imam Ismail and his son. According to W.Ivanow in 'The Rise of the Fatimids' (Calcutta, 1942, p. 56), 'The idea of the hijab, or a dignitary, whose duty was to pretend to be the Imam, thus sheltering the real holder of the office.'

It must be known that the functions of the hijab in pre-Fatimid period was the same as the hujjat. The hijab was the most trusted, tested, devoted and reliable dignitary who was ostensibly assigned with high religious authority, posing as an Imam to the ordinary people, accepting oath of allegiance on behalf of the concealed Imam.

According to 'Kashfu'l-Asrar' by Jawbari, quoted by L. Massignon, Maymun al-Qaddah died in 210/825, leaving behind two sons, Aban and Abdullah.

De Lacy O'Leary writes in 'Short History of the Fatimid Khilafat' (London, 1923, p. 25) that, 'The Ismailians alone have inherited the accurate knowledge of secret mysteries bequeathed by Jafar as-Sadik to his son Ismail.' W. Ivanow writes in 'Ismailis and Qarmatians'(JBBRAS, Bombay, 1940, p. 59) that, 'The successors of Ismail were therefore compelled to pay more attention to the other aspect of Imam Jafar's heritage - the philosophical and esoteric theories, which were more in demand here. This probably defined the further course of the evolution of Ismailism, which though it never gave up its strictly Islamic substance, had, nevertheless, to reconcile it with the philosophy of the time.'

We have heretofore noted that Imam Muhammad al-Bakir had articulated the implication of the doctrine of taqiya in Shiism, and we may attribute the rudiments of its theory to him. But it left to his son, Jafar Sadik to give it a final form abreast of time and make it an absolute condition of the faith.
Looking the changing condition radically then prevailing in the Arab society, it was a wise move by Imam Jafar Sadik to broach his followers the doctrine of taqiya (precautionary dissimulation), and made it the Shiite article of faith. He is reported to have said that, 'Taqiya is of my religion and of the religion of my forefathers. One who does not keep taqiya he has no religion.' He also said on another occasion that, 'Fear for your religion and protect it with taqiya.' He further said, 'Our belief concerning taqiya is that it is obligatory and he who forsakes, it is in the same position as he who forsakes prayer.'

Jafar Sadik had certainly worked out that an open dawat based on esoterism in the line of Ismail would mean a sure doom in the powerful Abbasid regime. It was, of course, risky for the Imams and their followers to openly propagate their minoritarian beliefs then onwards, therefore, the secret mission system was introduced with the help of taqiya, which could also avoided great deal of persecution. Farhad Daftary writes in 'The Ismailis: their History and Doctrines' (London, 1990, p. 85) that, 'The practice of taqiya conveniently protected the Shi'is, especially the later Ismailis, from persecution, and served in the preservation of their sectarian existence under hostile circumstances.'

The word taqiya is derived from the root tuqat, means 'conceal' or 'hide'. It is also suggested that it is rooted from waqqa, means 'keep or guard from someone'. The Koranic term tauqqat is also taken in the meaning of taqiya, to which divergance of opinions have been advanced. Baidawi (d. 685/1286) writes in his 'Anwar al-Tanzil' that, 'The qirah of Imam Yaqub (d. 205/820) contains the word taqiyainstead of tauqqat.' Similar word is also traced in the meaning of taqiya in Bukhari (vide 'Kitab al-Iqrah', 28:50). Ibn Hajar (d. 852/1449) also admits in 'Fateh al-Bari' (28:50) that tauqqat and taqiya are same in meaning. Zamakhshari (d. 538/1144) in 'Tafsir al- Kashshaf' (Cairo, 1953, 2nd vol., p. 16), Raghib Ispahani (d. 502/1108) in 'Tafsir al-Gharaib al-Koran' (Cairo, 1894, 1st vol., p. 313), Baidawi (d. 685/1286) in 'Anwar al-Tanzil' (Beirut, 1958, 1st vol., p. 153) and Fakhruddin Razi (d. 606/1209) in 'Tafsir al-Kabir'(Cairo, 1890, 2nd vol., p. 646), etc. have concured the doctrine of taqiya permissible in Islam in the light of the Koranic verse, which reads:- 'Let not the believers take the unbelievers for friends rather than believers, and whoever does this, he shall have nothing of God, except when you have to guard yourselves against them for fear' (3:27).

Another Arabic word kitman is also used for taqiya. The Arabic lexicons however render the meaning of taqiya as 'to arrange for protection.' In sum, taqiya is a practice permissible in Islamic jurisprudence. It is a doctrine allowing the disciples to conceal their faith during the time of trouble. According to 'Urdu Encyclopaedia of Islam' (6th vol., p. 581), 'The Shiites were suspected in some matters in non-Shiite rules, therefore, the doctrine of taqiya exercised special importance among them.'

Imam Jafar Sadik also then seems to have realized the significance of a tight, well-knit and secret organisation to face the emerging challenges in Arab society. For that purpose, he employed his Iranian client (mawla), named Maymun al-Qaddah, who had a skill for organising the vast network of an underground mission. The Arabs, it must be noted, were not traditionally and temperamentally suited for secretive and underground functionings. They had always lived in an open and free society in the desert without the paraphernalia of state and political intrigues. Comparatively, the character of the Abbasid empire at the same time, was also different from that of the Umayyads in as much as it was an empire of neo-Muslims of which the Arabs were only a part. It was mainly due to the support and strategy of the non-Arabs sections of people of Iran that the Abbasid succeeded in establishing their empire, chiefly by Abu Muslim Khorasani, who did much to bring the Abbasids to power

Besides, it is also known that Ismail had to assume the pseudonym of al-Mubarak in certain cases to protect his life. Al-Mubarak was a servant of Ismail in Medina, and a potential dai too. Very little is known about him. He was however hailed from Hijaz and an expert in Arabic calligraphy of the type known as muqarmat. In all probability, al-Mubarak was also the epithet of Ismail. More evidence of the application of the name al-Mubarak to Ismail have now come to light, lending strong support to W.Ivanow's hypothesis, vide 'The Alleged Founder of Ismailism' (Bombay, 1946, pp. 108-112), describing that, 'I have happened upon such clear and unequivocal testimony concerning al-Mubarak. The fact that it was in reality the surname of Ismail b. Jafar is revealed in at least four different passages in the early Ismaili esoteric work, 'Sullamu'n-Najjat' by Abu Yaqub as-Sijistani' (p. 111). It can be also ascertained from another work of Abu Yaqub as-Sijistani, entitled 'Ithbat al-Nubuwwat' (ed. Arif Tamir, Beirut, 1966, p. 190). Farhad Daftary also writes in 'A Major Schism in the Early Ismaili Movement' (Stvdia Islamica, Paris, LXXVII, 1993, p. 127) that, 'It has now become evident that the name Mubarak (the blessed) was the epithet of Ismail himself and it was applied as such to him by his followers.'
Hence, another small following of Ismail became known as Mubarakiyya. The Fatimid Imam al-Mahdi had routed a letter in Yamen after 308/921, which is reproduced by Jafar bin Mansur al-Yamen in 'al-Fara'id wa Hudud ad-Din' (pp. 13-19), in which the Imam has also disclosed that the Imams descending from Jafar Sadik wished to resuscitate the true dawat, and feared the treachery of hypocrites, therefore, they assumed names other than their own, and used for themselves esoterically names denoting the rank of proofs (hujjats) and styled themselves as Mubarak, Maymun and Sa'id because of the good omen in these names.

The terms Mubarakiyya and Khattabiyya therefore, were the original names of the nascent Ismailism, as well as the regional identifications of the followers of Ismail, who, on the whole, merged into the main fold of Ismailism in the time of Imam Muhammad bin Ismail. Concluding his judgment, al-Mutawakkil (532-566/1137-1170) writes in his 'Kitab Haqa'iq al-Marifa' as quoted by Bernard Lewis in 'The Origins of Ismailism' (London, 1940, p. 35) that, 'The Ismailiyya are the Mubarakiyya and the Khattabiyya.'

Returning to the thread of our main narrative, it is seen from the scrutiny of the historical traces that Ismail mostly lived in Salamia, and then moved to Damascus. Mansur knew his whereabouts, and wrote to his governor to arrest Ismail, but the latter quitted Damascus for Basra. Ismail's presence in Basra had been noticed by the people in 151/769. According to 'Tarikh-i Jhangusha', 'A paralytic begged alms of him. Ismail took him by the hand and he was healed; and rising to his feet he departed in his company. Ismail also prayed for a blind person and he recovered his sight.'

Abul Khattab Muhammad bin Abi Zaynab Maqlas al-Asadi al-Kufi (d. 167/783), surnamed Abul Khattab was an eminent disciple of Jafar Sadik. He was first to have preached the Shiite doctrines tinctured with esoteric interpretation. For quite some time, he was closely associated with Jafar Sadik, who had commissioned him as his chief dai in Kufa. Kashi narrates that once Imam put his hand on Abul Khattab's breast, and said: 'You know the mystery (ghayb).' This may be linked with Nawbakhti's expression that Imam revealed to him a solemn word (ism-i azam), and also called him the 'casket of our knowledge, the lodging place of our secrecy, the one who is trusted with our people's life and death.' One can thus easily judge the status of Abul Khattab before Jafar Sadik.
Soon afterwards, it is related that Jafar Sadik disliked his so called habit of never transmitting intact and unaltered the tradition which he heard, causing his relation with the Imam strained, and was excommunicated in about 138/755. This is perhaps an earliest glaring example of taqiya in Jafar Sadik's time, revealing outwardly a rupture between him and the Imam, to which some historians hazarded wrong opinion and concocted false stories around it. This sort of a taqiya seems to have intended to make the Shiite to dissociate themselves from Abul Khattab, and to make the Abbasids to implant in minds a consideration that there was no relation between Abul Khattab and Jafar Sadik. Abul Khattab's faith however was deep-rooted that had been never wavered for a single moment.

It is related that when Ismail had been in Iraq, he adopted the title of Abul Khattab most probably after 151/769 for exercising taqiya. Granted that Abul Khattab was not a secret follower of Jafar Sadik, then why Ismail assumed his name? Ismail henceforward, became known as Abul Khattab among the small group in Kufa, while Abul Khattab hid his identity. Nawbakhti in 'Kitab Firaq al-Shia' (ed. Ritter, Istanbul, 1931, pp. 60-61) and al-Qummi (d. 300/912) in 'Kitab al-Maqalat wa'l-Firaq' (ed. M.J Mashkur, Tehran, 1963, p. 83) write that the followers of Abul Khattab (i.e., Ismail) became known as Khattabiyya, believing that 'the divine light had transferred from Jafar Sadik into Abul Khattab, and on the death of the latter, it passed into Muhammad bin Ismail.' The term Abul Khattab here in reality was the epithet of Ismail. In Central Asia, a treatise 'Ummu'l-Kitab' is preserved among the Ismailis in which the Khattabiyyas are mentioned as the founders of Ismailism. It states further that the Ismailism was founded by the children of Abul Khattab, who gave their lives for the love of Ismail.

It is related that seventy followers of Abul Khattab had assembled in the mosque at Kufa, who had been killed by order of the governor. Abul Khattab was also captured and crucified. It is impossible to confess the notion advanced by the historians that his death took place in 138/755 or 145/762. He was killed most possibly in 167/783

Ismail Bin Jafar Sadik (148-158/765-775)- The line of Musa Kazim
- Abul Khattab
- Al-Mubarak
- The doctrine of taqiya
- Maymun al-Qaddah
- Death of Ismail
- Muhammad Bin Ismail (158-197/775-813)
- The Qaddahid theory
- Sacrifice of Ishaq bin al-Abbas
- Muhammad bin Ismail in Nihawand
- Muhammad bin Ismail in Khuzistan
- Muhammad bin Ismail in Farghana
- Organisation of Ismaili Dawa
- Zubaida - wife of Harun ar-Rashid
- Muhammad b. Ismail - al-Imamu'n Natiq
- Wafi Ahmad (197-212/813-828)
- Beginning of Dawr-i Satr
- Wafi Ahmad in Salamia
- Ahmad bin al-Kayyal al-Khasibi
- Martyrdom of Imam's son and brother
- Search of the Imam
- Incomparable sacrifices
- TAQI Muhammad (212-225/828-840)
- Trend of philosophy in Islam
- Abu Tirmizi in Abbasid court
- Origin of the Mutazalism
- The Rasail Ikhwan as-Safa
- Radi Abdullah (225-268/840-881)
- Ahmad bin Abdullah bin Maymun
- Mission of Ibn Hawshab in Yamen
- Khalaf al-Hallaj
- Hidden Imams in Dawr-i Satr

Abdullah bin Muhammad, surnamed ar-Radi, Nasir or al-Wafi (True to one's word) was also known as ar-Radi Abdullah al-Wafi or Wafi Ahmad, was born in 149/766. The tradition relates that Wafi Ahmad was locally known as attar (druggist) in Nishapur and Salamia as well, a surname he earned after his profession in drug and medicine as a protection against his real position. He was however represented by his hujjat, Abdullah bin Maymun (d. 260/874). It is also learnt that he was called Muhammad bin Ismail among the Ismailis, who lived at remote distance and had not seen the Imams. He, being the son and successor of Imam Muhammad bin Ismail is admittedly asserted in the work of Tabari (3rd vol., p. 2218). His mother was Fatima, the daughter of Sarah, sister of Ishaq bin al-Abbas.The Abbasid caliph Amin (193-198/809-814) was murdered after ruling for 4 years and 8 months, thereupon, his foster brother, Mamun Rashid (198-218/814-833) became the next caliph, who transferred his capital to Khorasan in early period of his rule, and as a result he followed a mild attitude with the Alids. After coming to Baghdad, Mamun Rashid changed his mind, and followed the doctrines of Mutazilite. He was however a bitterest foe of the Ismailis.

Abu Abdullah Muhammad, surnamed ash-Shakir was born in 122/740 in Medina. He passed his early life with his grandfather for 24 years and 10 years with his family in Medina. He however kept himself silent (samit) so long as he lived in Medina. He most probably left Medina soon after the death of his grandfather in 148/765.
The Abbasid caliph Mansur also died in 158/775 and was succeeded by his son Mahdi, who according to Ignaz Goldziher in 'Muslim Studies'(London, 1971, 2nd vol., p. 106), 'was listed by Ibn Adi as an inventor of hadiths.' He also died in 169/785 after ruling for 22 years, and was succeeded by his son, Hadi. He died in 170/786, and then his brother, Harun ar-Rashid became the next ruler till 193/809. He was also succeeded by his son, Amin.

The inimical opposition of the Abbasids against the Ismaili Imams was vigorously in continual. Abul Faraj Ispahani writes in 'al-Aghani' (12th vol., p. 17) that, 'Harun al-Rashid demanded of his poets that they combine his own praise with refutation of the claims of Ali's descendants and with attacks against the latter.' Abul Faraja further writes that, 'Harun ar-Rashid permitted himself to be glorified with things by which the prophets were praised; he did not disapprove of it and did not refuse it.' (Ibid. 12th vol., p. 18)

The most earliest description of Muhammad bin Ismail is found from the work of Tabari (3rd vol., p. 2218), and in the Ismaili sources summed up in the 4th volume of 'Uyun'l-Akhbar' (comp. 842/1438). Accordingly, Muhammad bin Ismail resided in Medina from where he sent his dais not only to spread Ismailism, but to search for a land of refuge where he could live unscathed. When Harun ar-Rashid learnt news of it, he sent his officials to arrest and bring the Imam to his court. When the caliph's men came to the house to carry out the orders, Muhammad bin Ismail entered an underground passage he had constructed inside his house and remained concealed until they had left. When the search for him had abated, he started on his journey, leaving behind his two sons. His whereabouts had been kept a closely guarded secret only the few specially privileged being acquainted with it and even they being pledged to the strictest secrecy.

It has been heretofore discussed that Musa Kazim had been staged as an Imam by the Abbasids on the ground of the fabricated theory of change of nass. The Abbasids had instituted an intensive search for Ismail, because they were well aware that Musa Kazim was not the true successor, otherwise he would have been executed very soon. They however failed to trace out Ismail and his son Muhammad. On the other side, the Abbasids noticed its reverse effect in Medina, where Musa Kazim was being truly adhered as an Imam. In the time of Harun ar-Rashid, finally Musa Kazim was arrested, who died in prison in 183/799. He should have been arrested and executed in 148/765, had he been truly succeeded his father.

Cyril Glasse writes in 'The Concise Encyclopaedia of Islam' (London, 1989, p. 197) that, 'The followers of Ismail, whose conception of the Imam was more absolute than that of the other Shiites, maintained on the contrary that the next Imam should be Ismail's son.'