Name - Muhammad
Title - At-Taqi and Al-Javad
Kunyat - Abu Jafar
Born - Friday 10th of Rajab 195 A.H. , at Medina
Father's Name - Ali ibn Musa
Mothers Name - Khaizuran
martyrdom - At the age of 25 years, at Kazmain , on Wednesday, 29th Zilqad 220 AH. Poisoned by Mu"tasin the Abbaside Caliph
Buried - in Kazmain, Bagdad.
Imam al-Javad (A.S.) was born on 10th day of the month of Rajab, in the year 195 A.H. in Madina - the city of his grandfather, the Messenger of Allah (S.A.W.), under the care of his father, Imam Ali bin Musa al-Reza (A.S.) who was qualified with the leadership (Imamate) and its qualifications, a lofty status, the position of leadership in the ummah and in the sciences of Islamic Sharia and its laws.
The Imam (A.S.) was born in a period full of events and political situations, conflicts, and the tension of events of the Abbasid caliphate between Amin and Ma"moon, the two sons of Harun Rashid.
Those political events and the situations of the conflict which was going on between the two brothers, the Abbasid caliphs, never ended without reflecting their effects on the life of Imam al-Reza (A.S.) attracted the attention of the Muslims -in the city of his grandfather, the Messenger of Allah (S.A.W.) - including religious scholars, jurisprudents, governors, and common people. Thus, the political view of the caliph, Ma"mun, was directed towards him and, therefore, summoned him to the capital of his rulership (Merv) in the year 200 A.H. and appointed him as heir so that the caliphate would be transferred to him after Mamun"s death.
The Imam Reza (A.S..) was forced to leave Madina and move towards the city of "Merv" (in Khurasan - Iran) to accept Mamun's invitation after many refusals and abstentions. Before moving to merv, he took with him, his son, Imam Muhammad al-Jawad (a.s.), then, he (a.s.) started out from Madina towards Mecca in order to pay a visit to the Sacred House (Kaba) and, also, to say farewell to it.
Imam al-Reza (A.S.) performed the hajj (pilgrimage) with his son, al-Jawad, who was only four years at that time.
Indeed, the young Imam expressed his adherence and love for his father by his insistence to stay under the care of the holy embrace. It was difficult for him to return home (Madinah), alone, and depart from his father, who wrote, in his farewell letter to the Sacred House, that he would not return.
The moments of farewell ended and the hour of departure approached; the young Imam al-Javad(A.S.) returned home (to Madinah), bearing the yearnings of love, the adherence of a son for his father; his father moved towards the city of Merv while his heart departed to Madina, following the procession of the beloved al-Jawad.
Imam al-Reza's Letters to his Son, al-Javad (A.S.)
Arriving at the city of Merv, the, then, capital of the Abbasid caliphate, Imam al-Reza (A.S.) rested there while his heart still inclined towards his son. From there, he (A.S.) began to correspond, address, advise, guide and take care of him. Historians state the fact that Imam al-Reza (A.S.) used to address his son al-Javad (A.S.), with honour and glory in his correspondences and call him by his surname "Abu Jafar".
source : www.tebyan.net
