He was born inMedina in the year 83 A.H and he died in Rajab in the year 148 A.H. at the age of 65. He was buried in the cemetery of Baqi' alongside his father, his grandfather and his (great-great) uncle. His mother was Umm Farwa, the daughter of Qasim bin Muhammad bin Abi Bakr. His Imamate lasted for thirty-four years. His father, Imam Mohammad Baqir (pbuh), clearly gave him the trusteeship of the Imamate and gave him an explicit designation for the Imamate.

Imam Jafar Sadiq (pbuh) stood out among their group for his great merit; he was the most celebrated, the greatest in rank and the most illustrious of them in the eyes of both the non- Shiite and the Shiite. The people transmitted on his authority the religious sciences which travelers carried with them and thus his fame was spread throughout the lands. The learned scholars have transmitted on the authority of no other member of the ahl-al-bayt as much as they have transmitted on his authority. None of them met as many of the reporters of traditions as he did, nor did the latter transmit on their authority to the same extent as they transmitted on the authority of Imam Jafar Sadiq (pbuh). The specialists in tradition have gathered together the names of those who narrated on his authority, who were reliable despite differences in views and doctrines and they were four thousand men. The clear evidence for his Imamate was such that it overcame hearts and silenced the attempts of an opponent to denigrate it with doubts.

Teachings

During the imamate of the sixth Imam greater possibilities and a more favorable climate existed for him to propagate religious teachings. This came about as a result of revolts in Islamic Lands, especially the uprising of the Muswaddah to overthrow the Umayyad caliphate, and the bloody wars which finally led to the fall and extinction of the Umayyads. The greater opportunities for Shiite teachings were also a result of the favorable ground the fifth Imam had prepared during the twenty years of his imamate through the propagation of the true teachings of Islam and the sciences of the Household of the Prophet. The Imam took advantage of the occasion to propagate the religious sciences until the very end of his imamate, which was contemporary with the end of the Umayyad and beginning of the Abbasid caliphates. He instructed many scholars in different fields of the intellectual and transmitted sciences, such asZorarah,Muhammad bin Moslim,Mu'min Taq, Hisham bin Hakam,Aban bin Taghlib,Hisham bin Salim, Hurayz,Hisham Kalbi Nassabah, andJabir bin Hayyan, the alchemist. Even some importantSunni scholars such asSufyan Thawri,Abu Hanifah, the founder of the Hanafi school of law,Qadhi Sukuni,Qadhi Abu'l- Bakhtari, and others, had the honor of being his students. It is said that his classes and sessions of instruction produced four thousand scholars of hadith and other sciences. The number of traditions preserved from the fifth and sixth Imams is more than all the hadith, that have been recorded from the Prophet and the other ten Imams combined.

 Martyrdom

Toward the end of his life the Imam was subjected to severe restrictions placed upon him by the Abbasid caliph Mansour, who ordered such torture and merciless killing of many of the descendants of the Prophet who were Shiite that his actions even surpassed the cruelty and heedlessness of the Umayyads. At his order they were arrested in groups, some thrown into deep and dark prisons and tortured until they died, while others were beheaded or buried alive or placed at the base of or between walls of buildings, and walls were constructed over them. Hisham, the Umayyad caliph, had ordered the sixth Imam to be arrested and brought to Damascus. Later, the Imam (pbuh) was arrested by Saffah, the Abbasid caliph, and brought to Iraq. Finally, Mansour had him arrested again and brought toSamarra where he had the Imam(pbuh) kept under supervision, was in every way harsh and discourteous to him, and several times thought of killing him. Eventually the Imam (pbuh) was allowed to return to Medina where he spent the rest of his life in hiding, until he was poisoned and martyred through the intrigue of Mansour.

Upon hearing the news of the Imam's martyrdom, Mansour wrote to the governor of Medina instructing him to go to the house of the Imam (pbuh) on the pretext of expressing his condolences to the family, to ask for the Imam's will and testament and read it. Whoever was chosen by the Imam (pbuh) as his inheritor and successor should be beheaded on the spot. Of course the aim of Mansour was to put an end to the whole question of the imamate and to Shiite aspirations. When the governor of Medina, following orders, read the last will and testament, he saw that the Imam (pbuh) had chosen four people rather than one to administer his last will and testament: the caliph himself, the governor of Medina, 'Abdullah Aftah, the Imam's older son, andImam Musa Kazim(pbuh), his younger son. In this way the plot of Mansour failed.

Source: Tebyan