ALI IBN AL-HUSAYN ZAYN'L' ABIDIN (A.S)
The holy Imam was born on Saturday, the 15th Jamada-l-ula, 36 Hijri in Madina (31st October 658 A.D) and died at the age of 58 years,; poisoned by al-Walid ibn' Abdi'L-Malik ibn Marwan on 25th Muharran 95 A.H. buried in Jannat-ul-Baqi', in Madina. His mother is commonly known name was Shahr Banu, daughter of Yazdger III, the King of Persia, otherwise her real name was Shazanan quoted in most of the historical accounts.
The Holy Imam 'Ali Zaynu-l-Abidin is the fourth Apostolic Imam. His epithet was Abu Muhammad and was popularly titled as "Zainul'l-Abidin. Imam Zaynu'l' Abidin spent the first two years of his infancy in the lap of his grnadfather 'Ali ibn Abi Talib and then for twelve years he had the gracious patronage of his uncle, the second Holy Imam al-Hasan ibn 'Ali. In 61 AH, he was present in Karbala', at the time of the gruesome tragedy of the wholesale massacre of his father, his uncles, his brothers, his cousins and all the godly comrades of his father; and suffered a heartless captivity and imprisonment at the hands of the devilish forces of Yazid.
The Holy Imam Zaynu'l-Abidin lived for about thirty four years after his father and all his life he passed in prayers and supplication to Allah and in remembrance of his martyred father. It is for his ever being in prayers to Allah, mostly lying in prayful prostration, that this Holy Imam was popularly called "Sajjad". His collections of prayers to God, SAHIFA-E-SAJJADIA or SAHIFA-E-KAMELA are available in Arabic with English translation and reciting of any of the prayers takes one closer to the Almighty the creator. Through these prayers the Imam gave all the necessary guidance to the faithful during his seclusion.
When the brutal forces of Yazid's army had taken the ladies and children as captives, carrying them seated on the bare back of camels, tied in ropes; this Holy Imam, though sick, was put in heavy chains with iron rings round his neck and his ankles, and was made to walk barefooted on the thorny plains from Karbala to Kufah and to Damascuss; and even then this godly Soul never was unmindful of his prayers to the Lord and was always thankful and supplicative to Him.
On 25th of Muharram, 95 A.H. when he was in Medina, al-Walid ibn 'Abdi'l-Malik ibn Marwan, the then ruler got this holy Imam martyred by poison. The funeral prayers of this Holy Imam were conducted by his son the Fifth Imam, Mohammad al-Baqar and his body was laid to rest in the cemetry of Janntu''l-Baqi Medina.
"His Imamt was confirmed in several ways.One of these was that he was most meritorious (afdal) of the creatures of God, the Most High, after his father in traditional knowledge ('ilm ) and practice ('amal). The imamat belongs to the most meritorious (afdal) to the exclusion of less meritorious (mafdul) by rational proof. Among these there was the fact that he was more appropriate for authority by virtue of his father, al-Husayn, peace be on him, and more entitled to his position after him through the merit and lineage. The one who was entitled through the last imam has more right to his position than any one else through evidence of the verse of next of kin (Dhu al-arham) and the (Quranic) story of Zacharia, peace be upon him".
Kitabal Irshad, Shaikh Mufid. P.p.380-81.
"Another of (the facts which confirm his Imamat) is the necessity according to reason of the Imamat existing in every age. The claim of every (other) claimant to the Imamae during the time of Ali b. al Husayn, peace be upon them, was invalid and impossibility of there being any time without an Imam is confirmed by him (being the Imam). Another (of the fact which confirms his Imamat) is the fact that the Imamat is established in the offspring (itra) (of the family of Ali) exclusively by rational deduction and by a report on the authority of the Prophet, may God bless him and his family. Invalidity of the argument of those who claim it for Muhammad b. al- Hanafiyya, may God be pleased with him, through him (also) belonging to the offspring is established by the absence of the designation of it to him. Therefore it is established that it belongs to Ali b. al Husayn, peace be on them, since there was no claim for it for any other member of the offspring (of the family) except Muhammad, may God be pleased with him, his exclusion from it was on account of what we have already mentioned".