The campaign of the ‘Abbasids started in 111 AH. On the one hand, it contributed to the spread of Shi‘ism in the various territories of the Muslim world, and on the other, the acts of strangulation of the Umayyads were lessened. As a result, the Shi‘ah were able to have a relative breathing space.
During this period, the infallible Imams (‘a) laid down the Shi‘ah juristic and scholastic foundations and Shi‘ism entered a new stage.
In general, during the Umayyad period there was no split between the descendants of ‘Ali (‘a) and the descendants of ‘Abbas ibn ‘Abd al-Muttalib and there was no quarrel between them. In this regard Sayyid Muhsin Amin says: “The descendants of ‘Ali (‘a) and the descendants of ‘Abbas during the Umayyad rule were treading the same path. The people who assisted them believing them to be more qualified to the caliphate than the Umayyads were known as the Shi‘ah of Muhammad’s (S) progeny.
During this period, there was no difference in religious opinion between the descendants of ‘Ali (‘a) and that of ‘Abbas. But when the ‘Abbasids came to power, Satan hatched the seed of discord between them and the descendants of ‘Ali (‘a), and they perpetrated numerous acts of oppression against the descendants of ‘Ali (‘a). For this reason, the ‘Abbasid campaigners were calling the people to please the progeny of Muhammad (S) while recounting the states of oppression the Prophet’s (S) progeny were enduring. Abu’l-Faraj al-Isfahani says: After the killing of Walid ibn Yazid and the emergence of differences among the Marwanis (descendants of Marwan ibn al-Hakam), Banu Hashim’s campaigners and propagandists went to various places, and the first thing they were expressing was the merits of ‘Ali ibn Abi Talib and his descendants. The said to the people: “How could the Umayyads afford to kill and displace the descendants of ‘Ali?”
As a result, during this period Shi‘ism remarkably spread. Even the hadiths related to Hadrat al-Mahdi (‘a) spread rapidly among the people of various regions. Khurasan was the main sphere of activity of the ‘Abbasid campaigners. For this reason, the Shi‘ah numbers there increased rapidly to such an extent that, as narrated by Ya‘qubi, After the martyrdom of Zayd (ibn ‘Ali ibn al-Husayn) in 121 AH, the Shi‘ah in Khurasan were agitated and stirred up. The Shi‘ah publicized their belief. Many of the ‘Abbasid campaigners used to approach them and recount the crimes committed by the Umayyads against the progeny of the Prophet (S). This subject and news was imparted to people in every city in Khurasan by ‘Abbasid campaigners who went there and dreams and aspirations in this regard were seen and books were taught.
Mas‘udi also narrates a subject which expresses the spread and prevalence of Shi‘ism in Khurasan. He thus writes: “In 125 AH when Yahya ibn Zayd was killed in Juzjan, the people named all the male infants born in that year were named Yahya.”
The influence of the ‘Abbasids in Khurasan was greater as Abu’l-Faraj thus says while stating the profile of ‘Abd Allah ibn Muhammad ibn ‘Ali ibn Abi Talib: The Khurasani Shi‘ah thought that ‘Abd Allah was his father Muhammad al-Hanafiyyah’s heir and that he was the Imam, and appointed Muhammad ibn ‘Ali ibn ‘Abd Allah ibn al-‘Abbas as his successor, and that the successor of Muhammad, Ibrahim, was the Imam from whom the Imamate extents to the ‘Abbasids through inheritance.
As such, the bulk of the ‘Abbasid army was constituted by the Khurasanis. In this regard, Muqaddasi says: As God saw the oppression and injustice of the Umayyads against the family of the Prophet (S), He gathered an army from the different parts of that Khurasan and sent it to them at the darkness of the night. During the advent of the Mahdi there is more expectation from the people of Khurasan.
Given this, the Ahl al-Bayt (‘a) of the Prophet (S) had occupied a distinct position among the people such that after the victory of the ‘Abbasids, a person named Sharik ibn Shaykh al-Mahdi in Bukhara staged an uprising because of the ‘Abbasids’ acts of injustice against the progeny of the Prophet (S), saying: “We did not pay allegiance to them for us to commit oppression, shed the blood of people unjustly and commit acts against the truth.” He was repressed and killed by Abu Muslim.

1. Shi‘ism during the Period of Imam al-Baqir and Imam as-Sadiq (‘a)
The second period of the Imamate of Imam Muhammad al-Baqir (‘a) and the initial period of Imam Ja‘far as-Sadiq’s (‘a) Imamate coincide with the ‘Abbasid campaigns and ‘Alawi uprisings such as that of Zayd ibn ‘Ali, Yahya ibn Zayd, and ‘Abd Allah ibn Mu‘awiyah - one of the grandchildren of Ja‘far ibn Abi Talib at-Tayyar - and the emergence of Abu Muslim al-Khurasani as the deputy of the ‘Abbasid campaigners in Khurasan in inciting the people against the Umayyads.
Meanwhile, the Umayyads had internal factional disputes and problems among their supporters because there was a serious clash between the Mudhiris and Yamanis among the Umayyad supporters in their respective spheres of influence. These revolts and entanglements made the Umayyads negligent of the Shi‘ah.
As such, the Shi‘ah were able to enjoy a relative breathing space; relaxation from the state of intense dissimulation {taqiyyah}; reorganize themselves; and reestablish contacts with their leaders.
It was at this period when the people turned toward Imam al-Baqir (‘a) to benefit from the blessings of which they had been deprived for many years. The Imam (‘a) rose up in order to keep alive the school {maktab} of the Ahl al-Bayt (‘a). He (‘a) engaged in guiding and enlightening people conducting teaching sessions in Medina and Masjid an-Nabi in particular. He served as the reference authority for people, solving their scientific and juristic problems, as such his view served as proof for them. Qays ibn Rabi‘ narrates that he asked Abu Ishaq about wiping {masa’} of slippers (during the performance of ablution {wudhu‘}) and Abu Ishaq said:
Like other people, I used to wipe my slippers (in ablution) until such time that I met a man from the Banu Hashim whose equal I have never met before. I asked him about the case of wiping the slippers (in ablution). He prohibited me from doing it, saying: “The Commander of the Faithful did not do it.” From then on, I stopped doing it.
Qays ibn Rabi‘ also says: “After hearing this statement, I also stopped wiping my slippers (in ablution).”
A certain man from among the Khawarij (Kharijites) came to Imam al-Baqir (‘a). While addressing the Imam (‘a), he said: “O Abu Ja‘far! What do you worship?” The Imam (‘a) said: “God.” The man asked: “Can you see Him?” The Imam (‘a) replied: “Yes, but the vision cannot witness Him while hearts with the truth of faith can see Him. He cannot be discerned through analogy {qiyas}. He cannot be perceived through the senses. He is not like human beings…” The Kharijite man left the Imam (‘a) while saying: “God knows well to whom He shall entrust His message {risalah}.”
The scholars such as ‘Amru ibn ‘Ubayd, Tawus al-Yamani, Hasan al-Basri, and Nafi‘ Mawla ibn ‘Umar used to refer to the Imam (‘a) for solving scientific and juristic problems and issues.
When the Imam (‘a) would arrive in Mecca, people would rush to ask him questions on matters pertaining to the lawful {halal} and the prohibited {haram}, considering the chance of asking the Imam (‘a) a boon and a means of acquiring more knowledge. Imam al-Baqir’s (‘a) teaching sessions were attended not only by students but also the scholars of the time. When Hisham ibn ‘Abd al-Malik arrived in Mecca for Hajj, he witnessed these teaching sessions that were an opportunity for him.
He sent someone to ask the Imam (‘a) on his behalf as to what the people will be eating on the Day of Judgment {mahshar}. In reply the Imam (‘a) said: “On the Day of Judgment there are trees whose fruits shall be eaten by the people and rivers whose water the people shall drink so as to feel easiness for the Reckoning.” Hisham again sent that person to ask the Imam (‘a), hence: “Shall the people have time to eat and drink?” The Imam (‘a) said: “Even in hell there shall be opportunity to eat and drink, and the dwellers of hell shall also ask for water and other graces of God.”
Zurarah (ibn A‘yan) says: I, along with Imam al-Baqir (‘a), was sitting beside the Ka‘bah, while the Imam (‘a) was facing the Ka‘bah. The Imam (‘a) said: “Looking at the Ka‘bah is indeed an act of worship.” Then a certain man (from Bajilah) came and said: “Ka‘b al-Ahbar used to say: ‘The Ka‘bah prostrates to the Temple of Jerusalem everyday’.” The Imam (‘a) said to the man: “What do you think about what Ka‘b was saying?” The man answered: “Ka‘b was telling the truth.” The Imam (‘a) was annoyed and retorted, saying: “No, you have lied and Ka‘b has lied.”
Great ‘ulama’, jurists {fuqaha} and hadith scholars {muhaddithun} were trained under the blessed feet of the Imam (‘a), such as Zurarah ibn A‘yan about whom Imam as-Sadiq (‘a) said: “If it were not for Zurarah, there was a probability for the hadiths of my father to be lost forever.”
Muhammad ibn Muslim heard thirty thousand hadiths from Imam al-Baqir (‘a). Another scholar who learned from the Imam (‘a) was Abu Basir about whom Imam as-Sadiq (‘a) said: “Had it not been for them, the works of prophethood {nubuwwah} will be terminated and be antiquated.”
Other prominent figures such as Yazid ibn Mu‘awiyah al-‘Ajali, Jabir ibn Yazid, Hamran ibn A‘yan, and Hisham ibn Salim were among those who were trained in the school {maktab} of the Imam (‘a).
In addition to the Shi‘ah scholars, many of the Sunni ‘ulama’ have also studied under the Imam (‘a) and narrated hadiths on the authority of the Imam (‘a). As Sabt ibn al-Jawzi says, “(Imam) Ja‘far used to narrate hadiths of the Prophet (S) from his father.” As such, a number of the Followers {tabi‘un} such as ‘Ata’ ibn Abi Rubah, Sufyan ath-Thawri, Malik ibn Anas (founder of the Maliki school of thought {madhhab}), Shu‘bah, and Abu Ayyub Sijistani have narrated hadiths from the Imam (‘a).
Furthermore, thousands of learned men in jurisprudence and hadith attained progress in the Imam’s (‘a) school and his hadiths were spread far and wide so much so that Jabir al-Ju‘fi, who was a great muhaddith, has narrated seventy thousand hadiths on the authority of the Imam (‘a). This state of affairs continued until Imam al-Baqir (‘a) attained martyrdom on Dhu’l-Hijjah 7, 114 AH.

The University of Imam as-Sadiq (‘a)
In view of the then prevailing conducive political atmosphere, Imam Ja‘far as-Sadiq (‘a) pursued his father’s scientific movement and established a large university and center of learning whose horizon reached far and wide. Shaykh al-Mufid says: The knowledge of the Imam (‘a) has been so widely narrated that it became proverbial to various many and its fame spread to every nook and corner. None of the progeny of the Prophet (S) match him (in this regard) whose knowledge and learning have been so widely transmitted.
Amir ‘Ali thus writes about the Imam (‘a): Those philosophical discussions and debates in all the Islamic centers became widespread and the guidance and instructions given in this regard were made possible only by the university that has been established in Medina under the supervision of Hadrat Sadiq, a great grandchild of Hadrat ‘Ali. He has been one of the great ‘ulama’ with precise views, a deep understanding, and well-versed in all the branches of knowledge of the time. In reality, it is he who is the founder of the rational academy in Islam.
As such, those who were lovers of knowledge {‘ilm} and thirsty for the Muhammadan (S) gnosis {ma‘rifah} rushed from different parts of the then Muslim world to that heroic Imam (‘a) in multitude, and benefited from his abundant spring of knowledge and wisdom. Sayyid Ilahil says: “In Kufah, Basrah, Wasit, and Hijaz, people of every tribe sent their children to Ja‘far ibn Muhammad. Many of the Arabs and Persians, the people of Qum in particular, came to him.”
In his Al-Mu‘tabar, the late Muhaqqiq (al-Hilli) thus writes: During the period of Imam as-Sadiq (‘a) various branches of knowledge that were transmitted from him astonished the great thinkers. A group of about four thousand rijali scholars have narrated hadiths from him, and by his teachings a great number of people in the various sciences attained mastery to such an extent that his answers to their questions were compiled in four hundred books {musannafat}, which were called “Usul”.
In his book, Dhikra, Shahid al-Awwal also says: “Four thousand people from Iraq, Hijaz, Khurasan, and Sham put into writing the answers of Abu ‘Abd Allah Imam as-Sadiq (‘a) to the questions.”
In this manner, the seekers and lovers of knowledge and learning used to benefit from the Imam (‘a). Outstanding scholars in various branches of the revealed {naqli} and rational {‘aqli} sciences of the day such as Hisham ibn Hakam, Muhammad ibn Muslim, Aban ibn Taghlib, Hisham ibn Salim, Mu’min Taq, Mufadhdhal ibn ‘Umar, Jabir ibn Hayyan, etc. were trained under the blessing of his presence.
Their compilations which are known as the Usul Arba‘ami’ah, are the basis of the four Shi‘ah books on hadith, viz. Al-Kafi, Man La Yahdharah al-Faqih, At-Tahdhib, and Al-Istibsar.
The disciples of Imam as-Sadiq (‘a) were not all Shi‘ah as most of the Sunni scholars of the day have also studied under his guidance. Ibn Hajar al-Haythami, a Sunni author, thus writes in this regard: “The leading figures (in jurisprudence and hadith) such as Yahya ibn Sa‘d, Ibn Jarih, Malik, Sufyan ath-Thawri, Sufyan ibn ‘Uyaynah, Abu Hanifah, Sha‘bi, and Ayyub Sijistani have narrated hadiths on his authority.”
Abu Hanifah, the founder of the Hanafi school of thought, has said: I used to go to Ja‘far ibn Muhammad for sometime. I used to see him in one of the three conditions: either he was praying, in the state of fasting, or reading the Qur’an. I never saw him narrating the hadith without performing ablution. The one superior to Ja‘far ibn Muhammad in knowledge, devotion and piety has not been seen by any eye, heard by any ear, or perceived by any heart.
The Imam’s (‘a) teaching sessions were attended by those who later founded schools of jurisprudence attending as philosophers, as well as students of philosophy from far and wide. After learning the sciences from their Imam (‘a), they would return to their homelands and conduct teaching sessions of their own.
The Muslims used to gather around them and they in turn impart the teachings of the Ahl al-Bayt (‘a) propagating Shi‘ism. When Aban ibn Taghlib would come to Masjid an-Nabi, the people would reserve for him the pillar against which the Prophet (S) used to lean, and he would narrate hadiths to them. Imam as-Sadiq (‘a) used to say to him: “Sit in the mosque of Medina and issue religious edicts to the people as I like persons like you to be seen among my Shi‘ah.”
Aban was the first person to have written something on the sciences of the Qur’an {‘ulum al-Qur’an} and he was also so well-versed in hadith that he used to sit in Masjid an-Nabi and the people would come and ask him. Through his various styles of speaking, he would answer them and impart the hadiths of the Ahl al-Bayt (‘a) to them.
In Mizan al-I‘tidal, adh-Dhahabi thus says regarding him: “If the hadith of individuals such as Aban who are accused of being Shi‘ah is rejected, a great part of the Prophetic works would have perished.”
Abu Khalid al-Kabuli says: “I saw Abu Ja‘far Mu’min Taq sitting in Masjid an-Nabi while the people of Medina gathered around him and posed their questions on jurisprudence {masa’il} to him and he would answer them.”
Shi‘ism during that period was so spread that some people, in a bid to acquire social standing among the people, resorted to fabricating hadiths from the Imams (‘a) to draw people’s attention by interpreting the traditions in their own favor.
For example, Imam as-Sadiq (‘a) - in reply to one of his companions named Faydh ibn Mukhtar who asked about the reason behind the contradiction in hadiths - thus says: “These people are not seeking the pleasure of Allah in narrating the hadiths and expressing our views. They are rather seeking the world and each of them is aspiring to be leader.”

Summary
The ‘Abbasid campaign started in 111 AH. During that time, there was no division between the descendants of ‘Ali {‘Alawi} and the descendants of ‘Abbas ibn ‘Abd al-Muttalib {‘Abbasi}. The Umayyads were busy repressing the ‘Abbasid uprisings as a result of which Shi‘ism spread remarkably.
Imam al-Baqir and Imam as-Sadiq (‘a) in this opportune time trained their disciples establishing the Jafari University, and many jurists {fuqaha} and scholastic theologians {mutakallimun} benefited from these two personages. Shaykh al-Mufid regards the number of the disciples of Imam as-Sadiq to be four thousand.