Jafar ibn Muhammad

Jafar ibn Muhammad (; 702-765), also known as As-Sadiq ("The Truthful") was the sixth Shia imam. He was the grandson of Zayn al-Abidin and the descendent of Ali ibn Abi Talib on the side of his father and Abu Bakr on the side of his mother. He is highly respected among both the Sunnis and the Shias. He was a spiritual person, hadith teller and a jurist. 
&lt;br&gt;After the death of Jafar ibn Muhammad, division occurred among Shias on the question of next Imam. Some said that his eldest son, Ismail ibn Jaffar (who had died before his father) to be the next imam, while the majority of Shiites said that his third son Musa al Qazim should be the next imam. The first group became known as the Ismailis and the second, larger group was named Jafari or the Twelvers.