Birth and family life
On the eleventh of
Dhu al-Qi'dah, 148 AH (December 29, 765 CE), a son was born in the house of Imam Musa al-Kadhim (the seventh Imam of
Shia Islam) in
Medina. He was named Ali and titled al-Ridha, however in the Shia sources he is commonly called Abu’l-Ḥasan al-Ṯānī so as not to be confused with his father, Imam
Musa al-Kadhim. His father was known as Abu’l-Ḥasan al-Awwal. He was born one month after the death of his grandfather,
Ja'far as-Sādiq, and brought up in Medina under the direction of his father.
 His mother, Najmah, was also a distinguished and pious lady. It is said that the boy al-Ridha required a great deal of milk, so that when his mother was asked whether her milk was sufficient, she answered, "it is not because my milk is not sufficient, but he wants it all the time, and consequently I am falling short in my prayers."
 She was originally a
Berber (from the
 She was purchased and freed by Bibi Hamidah Khatun, the wife of Imam
 and like Bibi Hamidah was a notable Islamic scholar.
Disputes exist regarding the number of his offspring and their names. A group of scholars(Sunni) say that they were five sons and one daughter, and that they were: Muhammad al- Qani', al-Hasan, Ja’far, Ibrahim, al-Husayn, and 'Ayesha.
Sabt ibn al-Jawzi, in his work Tadhkiratul-Khawass("
تذکرۃ الخواص-Introduced eminence of the heirs of Muhammad The Prophet of Islam), says that the sons were only four, dropping the name of Husayn from the list.
Surname and father-name
He described among
Shia Narrations as the second abul hasan in contrary of first Abul Hasan (according to Sunni scholars the name Abu Hasan is because of his son's name Hasan) who was his father Imam
Musa Kazim. Also there are other honorific titles attributed to him such as Saber, Vafi, Razi, Zakki amd Vali