His blessed name is Ali and his nicknames are Zeynolabedin and Sadjad. His honorable father is Imam Hussein bin Ali (A.S) and his dignified mother is Shahrbanu, daughter of Yazgerd the last king of Sassanid Dynasty. He was born on Sunday 15th of Jamadi al-Ula or Sha'ban 5th of Hegira year 38 in Medina. Imam Sadjad (A.S) was martyred on Muharram 25th of Hegira year 94 or 95 in Medina at the age of 57. His tenure of imamate was 34 years. Imam Sadjad's grave is in Baqi' Cemetery, Medina.
Imam Sadjad (A.S) gained great achievements in safeguarding the culture of Ashura. For instance, he presented epical, fervent and influential sermons. Undoubtedly enlightening narrations of Imam Sadjad (A.S), Hazrat Zeinab (A.S) and some other relatives of Imam Hussein (A.S) on the sorrowful tragedy of Karbala have played a key role in continuation of that great Islamic movement.
The most important achievements of Imam Sadjad (A.S) were sowing the seeds of awareness, awakening the dormant consciences, revealing the crimes of the enemies of the Infallible Household of the Prophet (PBUH), presenting the true image of despotic Umayyad kings to the people, publicizing the merits and virtues of the Infallible Household of the Prophet (PBUH) and introducing them as the true successors of the Messenger (PBUH).
source : www.tebyan.net
