Al-Ḥusayn ibn ʿAlī ibn Abi Talib (ٱلْحُسَيْن ابْن عَلِي ابْن أَبِي طَالِب‎‎; 10 October 625 – 10 October 680; also transliterated as Husayn ibn Ali, Husain, Hussain and Hussein) was a grandson of the Islamic prophet Muhammad and a son of Ali ibn Abi Talib (the first Shia Imam and the fourth Rashid caliph of Sunni Islam) and Muhammad's daughter Fatimah. He is an important figure in Islam as he was a member of the Bayt (Household) of Muhammad and the Ahl al-Kisā' (People of the Cloak), as well as the third Shia Imam.

Hasan ibn Ali ibn Muhammad (c. 846 – 874) was the 11th Imam of Twelver Shia Islam, after his father Ali al-Hadi. He was also called Abu Muhammad and Ibn al-Ridha. Because Samarra, the city where he lived, was a garrison town, he is generally known as al-'Askari ('Askar is the word for military in Arabic).

Ali ibn Husayn (علي بن الحسين‎), also known as Zayn al-Abidin (the adornment of the worshippers) and Imam al-Sajjad (The Prostrating Imam), was the fourth Muslim Imam from Ahl al-Bayt, after his father Husayn ibn Ali, his uncle Hasan ibn Ali, and his grandfather Ali ibn Abi Talib. Ali ibn Husayn survived the Battle of Karbala in 680 CE, after which he and other surviving family members and companions of Husayn were taken to Yazid I in Damascus. Eventually, he was allowed to return to Medina, where he led a secluded life with a few intimate companions.

'Alī ibn Mūsā ar-Riḍā (Arabic: علي ابن موسى الرّضا‎), also called Abu al-Hasan, Ali al-Reza (c. 29 December 765 – 23 August 818) or in Iran (Persia) as Imam Reza (Persian: امام رضا‎), was a descendant of the Islamic prophet, Muhammad, and the eighth Shi'ite Imam, after his father Musa al-Kadhim, and before his son Muhammad al-Jawad.

ʿAlī ibn Abī Ṭālib (Arabic: عَلِيّ بْن أَبِي طَالِب; c. 600 – 661 CE) was the last Caliph of the Rashidun Caliphate, the successor state to the Islamic prophet Muhammad's political dominions. He is considered by Shia Muslims to be the first Imam, the rightful religious and political successor to Muhammad.

Imam al-Ḥasan ibn Alī ibn Abī Ṭālib (الحسن ابن علي ابن أبي طالب‎‎, 624–670 CE), commonly known as Hasan or Hassan, is the eldest son of Muhammad's daughter Fatimah and of Ali, and the older brother to Husayn. Muslims respect him as a grandson of the Islamic Prophet Muhammad. Among Shia Muslims, Hasan is revered as the 2nd Imam.

Alī ibn Muḥammad ibn ‘Alī (Arabic: علي بن محمد بن علي‎‎; 829-868 C.E.) was the tenth of the Twelve Imams after his father Muhammad al-Jawad and before his son Hasan al-Askari. He remained in Medina teaching until the age of 30 when he was summoned to Samarra by the Abbasid caliph Al-Mutawakkil. There he was treated roughly by the caliph and his successors until, according to Shiite accounts, he was poisoned through intrigue of Al-Mu'tazz the Abbasid caliph, in 254/868, and was buried in Samarra.

Muḥammad al-Baqir, full name Muhammad bin 'Ali bin al-Husayn bin Ali bin Abi Talib, also known as Abu Ja'far or simply al-Baqir (Arabic: محمد الباقر‎, romanized: al-Bāqir, lit. 'the one who opens knowledge') (677-733) was the fifth Shia Imam, succeeding his father Zayn al-Abidin and succeeded by his son Ja'far al-Sadiq.