IV. The Fourth Imam, 'Ali, known as Zayn al-'Abidin and al-Sajjad (38/65895/7I2)
The son of Imam al-Husayn by the daughter of Yazdigird, the last Sassanid king of Iran, he was not able to carry arms at Karbala because of illness, and thus he was saved the fate of his three brothers. For most of his life he lived in seclusion in Medina, having contact with only a few select followers. His piety-which is reflected in his collected prayers, al-Sahifat al-sajjadiyyah -is proverbial. He is buried in the Baqi' cemetery in Medina.