Hussain ibn Ali was Muhammad's grandson and son of Fatima, the Prophet's daughter. His father was Ali ibn Abi Talib, Muhammad's cousin and devoted follower, who became the fourth Muslim caliph and the first imam of the Shi'i branch of Islam. The Shi'i revere Hussain as their third imam and as a martyr.
Ali b. al-Hussain b. Ali b. Abi Talib, Zayn al-Abidin (“Ornament of the Worshippers”), is the fourth Imam of the Twelver Shi’a. His kunya (his other names) is variously given as Abu Abd Allah, Abu Bakr, Abu’l-Hussain, Abu’l-Hasan, etc. According to most sources, he was born in 38/658-59 in Medina.
Hasan B. Ali B. Abi Taleb, was the eldest surviving grandson of the Prophet Muhammad through his daughter Fatima, and second Imam of the Shi’a after his father Ali.
Abbas B. Ali B. Abu Taleb (d. 61/680), known as Abu Fadl (father of excellence) and Qamar Bani l-Hashim (the Moon of Banu Hashim), was a half-brother of Imam Hussain who fought bravely at the battle of Karbala.