He survived the Battle of Karbala in 680, in which Husayn and his small caravan were massacred en route to Kufa by the forces of the Umayyad caliph Yazid I (r. 680–683).

Al-Sajjad was eventually allowed to return to his hometown of Medina, where he led a secluded life, without participating in the numerous pro-Alid uprisings against the Umayyads during the civil war of the Second Fitna.

Instead, he devoted his life to worship and learning, and was highly esteemed, even among proto- Sunnis, as a leading authority on Islamic tradition (hadith) and law (fiqh).

Being politically quiescent, al-Sajjad had few followers until late in his life, for many Shia Muslims were initially drawn to the anti-Umayyad movement of Mukhtar al-Thaqafi.

Some others followed Muhammad's much younger half-brother, Zayd ibn Ali, whose rebellion was crushed by the Umayyads in 740, marking the birth of Zaydism.

[4][5] Al-Sajjad's mother is named variously in sources as Barra, Gazala, Solafa, Salama, Shahzanan, and Shahrbanu.

[4][5] In contrast, Shia sources maintain that al-Sajjad’s mother a daughter of Yazdegerd III (r. 632–651), the last Sasanian Emperor,[5] who was overthrown during the Muslim conquest of Persia.

[5] Shia accounts add that Yazdegerd’s daughter was brought to Medina as a captive during the reign of the second caliph, Umar (r. 634–644).

[11] The captives were then presented to the Umayyad governor Ubayd Allah ibn Ziyad, who boasted of killing Husayn and his relatives,[12] calling it divine punishment.

[17][18] A letter to Yazid, attributed to Muhammad's cousin Abd Allah ibn al-Abbas, chastises the caliph for treating the captives poorly, suggesting that such treatment was worse than the massacre.

[22] The first narrative is that he treated the captives kindly after an initial, harsh interrogation, saying that he regretted the conduct of his governor, and that he would have pardoned Husayn if he were alive.

[22][23] In contrast, M. Momen, another expert, believes that Yazid, fearing social unrest, released the captives as public opinion began to sway in their favor.

[15] Similar views are expressed by some other authors, including J. Esposito,[20] R. Osman,[24] K. Aghaie,[25] D. Pinault,[16] H. Munson,[26] and the Shia scholar M. H.

At any rate, such claims of remorse are in stark contrast to Yazid's earlier orders to his governor to either exact homage from Husayn or kill him.

[28] The alternative narrative suggests that the captives were brought to the caliph in a ceremony, who gloated over avenging his pagan relatives killed fighting Muhammad.

[34] Ali al-Sajjad led a quiet and scholarly life after returning to Medina, confining himself to a small circle of followers and disciples.

[14] After the Karbala massacre, Abd Allah, the son of Zubayr, who was a prominent companion of Muhammad, declared himself caliph in the Hejaz.

He gradually gained popular support,[43][44] to the extent that in 683 the Kufans forcibly replaced their Umayyad governor with a representative of Ibn Zubayr.

[5][47] On this occasion, al-Sajjad, unlike others, was exempted from a renewed oath of allegiance to Yazid,[46] perhaps because he had earlier sheltered the Umayyad Marwan ibn al-Hakam and his family.

[5] Some non-Shia sources describe a friendly relationship between al-Sajjad and Marwan, who in 684 succeeded Yazid's sickly son in the caliphate.

In contrast, Shia sources contend that al-Sajjad interacted with authorities under the principle of religious dissimulation (taqiyya) to avoid persecution.

They revolted to atone for having deserted Husayn, meaning to deliver the caliphate to his son, al-Sajjad;[48][49] but they were crushed in 684 by a much larger Umayyad army.

[62] Ali al-Sajjad either died from natural causes,[63] or, as reported by Shia authorities, he was poisoned at the instigation of the reigning Umayyad caliph al-Walid (r. 705–715) or perhaps his brother Hisham (r. 724–743).

[92] Especially for early Zaydis, any (religiously) learned descendant of Ali ibn Abi Talib and Fatima qualified for leadership as long as he rose against the unjust government.

[102][98] Shia sources attribute some miracles to al-Sajjad: He spoke to a gazelle in the desert, restored youth to an old woman, and the sacred Black Stone in Mecca attested to his imamate in the presence of Ibn al-Hanafiyya.

[2][104] He spent much of his time in worship and learning,[105] to the point that his face was bruised and his legs were swollen from lengthy prayers, according to his Shia biographer.

[63] This was particularly the case within the learned circles of Medina,[107] such that among his associates and admirers were some top Sunni scholars of the time, including al-Zuhri and Sa'id ibn al-Musayyib.

[4] He bought and freed dozens of slaves in his lifetime,[2] and secretly provided for destitute Medinans, who discovered, after his death, that al-Sajjad was the benefactor who regularly brought them food at night, while covering his face to preserve his anonymity.

Shia tradition regards this book with great respect, ranking it behind only the Quran and Nahj al-balagha, which is attributed to Ali ibn Abi Talib.

[113] The book, attributed to al-Sajjad, is often regarded as authentic by Shia scholars of hadith,[113] although its whispered prayers (munajat) may have been artistically edited by others.