Umm Farwah bint al-Qasim
Umm Farwah bint al- Qasim or Umm Farwah Fatimah Muhammad al- Baqir, and the mother of the sixth Imam, Ja'far al- Sadiq.
Qudama ibn Ja'far
Qudama ibn Ja'far al- Katib al- Baghdadi( ca. 873 – ca. 932/948), was a Syriac scholar and administrator for the Abbasid Caliphate.
Isma'il ibn Ja'far
Ismāʿīl ibn Jaʿfar al- Mubārak( c. born: 719 AD, Medina- died circa 762 AD, Medina) was the eldest son of Imam Ja'far al- Sadiq.
He is also known as Isma'il Al- Ãraj ibn Ja'far( اسماعيل الاعرج ابن جعفر الصادق).
Following Ja'far's death, the Shia community split between those who believed the Imamate was passed to Musa ibn Ja'far, who would become the Twelver Shia, and those who believed that the Imamate passed to Isma'il ibn Ja'far, who would become the Isma'ili branch named after Isma'il.
Musa al-Kadhim
Musa ibn Ja'far al- Kadhim, also spelled and al- Kazim, and also known as Abu al- Hasan, Abu Abd Allah orAbu Ibrahim, was the seventh Shia Imam after his father Ja'far al- Sadiq who was also a shia.
He is regarded by Sunnis as a renowned scholar, and was a contemporary of the Abbasid caliphs Al- Mansur, Al- Hadi, Al- Mahdi and Harun al- Rashid.
He was imprisoned several times; finally dying in Baghdad in the Sindi ibn Shahak prison.
Ali al- Rida, the eighth Imam, and Fatemah al- Ma'sumah were among his children.
Muhammad ibn Abdullah al-Aftah
Muhammad ibn Abdullah al- Aftah ibn Ja'far al- Sadiq alias Maymūn Al- Qaddāḥ was a figure whose existence is contested: a portion of the Fathite Shia Muslims( followers of Abdullah al- Aftah ibn Ja'far al- Sadiq), believed that Muhammad was the son of Imam Abdullah al- Aftah( died 766 CE), whom they believed to be the Imam after his father Ja'far al- Sadiq.
This assertion is contested by others, including many Fathites, who believe that Abdullah died without issue.
When Abdullah al- Aftah died without an issue to succeed him in the Imamate, a portion of his followers believed in the necessity of the continuation of the Imamate in the children and the grandchildren of the Imam through pure vertical inheritance.
Due to this they could not shift to the belief in the Imamate of the brother of Abdullah al- Aftah, Musa al- Kadhim.
They therefore believed that Abdullah secretly had a son, claiming that this son was the Mahdi.
They argued:" His name corresponds to the famous Prophetic" hadith"( of Muhammad):
' His name( i.e. the Mahdi) is my name( i.e. Muhammad), the name of his father is the name of my father( i.e. Abdullah).'"
There maybe evidence that he had a son named Sayed Alawi.
Below is a detailed family tree.
Muhammad ibn Ja'far
Muhammad ibn Ja'far( Arabic: محمد بن جعفر) was a companion and relative of the Islamic prophet Muhammad.
He was the son of Muhammad's cousin, Ja'far ibn Abu Talib, and of Asma bint Umais.
His uncle Ali particularly wished that his daughters should marry Ja'far's sons.
In due course, Muhammad ibn Ja'far did marry Ali's daughter Umm Kulthum, who was the widow of his brother Awn.
They had no children.
Abdullah al-Aftah
Abdullah al- Aftah ibn Ja'far al- Sadiq( d. 766 CE/ 149 A.H.) was the eldest surviving son of Ja'far al- Sadiq( after al- Sadiq ’s death) and the full- brother of Isma'il ibn Jafar.
Abdullah ’s title al- Aftah derives from the Arabic words aftah al- ra ’s( broad- headed) or aftah al- rijlayn( broad- footed) used to describe his appearance.
Ali al-Uraidhi ibn Ja'far al-Sadiq
Ali al-Uraidhi ibn Ja'far al-Sadiq,  better known simply as Ali al-Uraidhi, was the son of Ja'far al-Sadiq and the brother of Imam Isma'il, Imam Musa al-Kadhim, Abdullah al-Aftah, and Muhammad Al-Dibaj.
He was known by the title al-Uraidhi, because he lived in an area called Uraidh, about 4 miles (or 6.4 km) from Medina.
He was also known by the nickname Abu Hasan (i.e. father of Hasan).
He was a great Muslim scholar.
Ahmad al-Muhajir
Ahmad al- Muhajir(',; 260-345 AH or 873-956 CE) also known as Al- Imām Aḥmad bin ʻ Isa was an Imam Mujtahid and the progenitor of Ba' Alawi sada group which is instrumental in spreading Islam to India, Southeast Asia and Africa.
He was the son of ‘ Isa the son Muhammad the son of' Ali al- Uraidhi who was the fourth son of Imam Ja'far as- Sadiq, a fifth generation descendant of Ali bin Abu Talib and Fatimah bint Muhammad, the daughter of Muhammad.
Ja'far al-Sadiq
Jaʿfar ibn Muḥammad aṣ-Ṣādiq (700 or 702–765 CE), commonly known as Ja'far al-Ṣādiq or simply as-Sadiq (The Truthful), was an 8th-century Muslim scholar and scientist.
He is considered as an Imam and founder of the Ja'fari school of jurisprudence by Twelver and Isma'ili Shi’as, and a major figure in the Hanafi and Maliki schools of Sunni jurisprudence.
He was a descendant of the Caliph Ali and Fatimah bint Muhammad on the side of his father, Muhammad al-Baqir, and of Muhammad ibn Abu Bakr on the maternal side of his family, Umm Farwah bint al-Qasim.
Muhammad ibn Abi Bakr was raised by Ali, but was not his son.
Ali used to say: "Muhammad Ibn Abu Bakr is my son but from Abu Bakr's lineage".
Al-Sadiq is the 6th Imam for Twelvers, is recognized by the majority of the Shi’a as an Imam, and is revered in Sunni Islam as a transmitter of hadiths, therefore a prominent jurist, and a mystic to Sufis.
Despite his wide-ranging attributions in a number religious disciplines, no works penned by Ja'far himself remain extant.
Al-Sadiq was born in either 700 or 702 CE.
He inherited the position of imam from his father in his mid-thirties.
As a Shi’a Imam, al-Sadiq stayed out of the political conflicts that embroiled the region, evading the many requests for support that he received from rebels.
He was the victim of some harassment by the Abbasid caliphs, and was eventually, according to Shi’a Muslims, poisoned at the orders of the Caliph Al-Mansur.
In addition to his connection with Sunni schools of Sunni jurisprudence, he was a significant figure in the formulation of Shia doctrine.
The traditions recorded from al-Sadiq are said to be more numerous than all hadiths recorded from all other Shia imams combined.
As the founder of Ja'fari jurisprudence, al-Sadiq also elaborated the doctrine of "Nass" (divinely inspired designation of each imam by the previous imam), and "Ismah" (the infallibility of the imams), as well as that of Taqiyyah.
The question of succession after al-Sadiq's death was the cause of division among Shi’a who considered his eldest son, Isma'il (who had reportedly died before his father) to be the next Imam, and those who believed his third son Musa al-Kadhim was the imam.
The first group became known as the Ismailis and the second, larger, group was named Ja'fari or the Twelvers.

Question: Who is Ali Al-Uraidhi Ibn Ja'Far Al-Sadiq's paternal grandfather?