Ibn Abi Aqil - Abu Muhammed al-Hasan b. Ali b. Abi Aqil al-Umani was an important Twelver Shi’a Jurist during the Minor Occultation period. He was also a contemporary of Muhammed b. Yaqub al-Kulayni and was also a renowned theologian and a narrator of Hadith. Ibn AbiAqil wrote important early works on Imamate, including “Kitab al-karrwa’lfarr,” and another theological essay defending the rights of the Ahlulbayt. According to Sayyed Mahdi Baher’lulum, Ibn AbiAqil was the first scholar to standardise Imami law.
Ibn al-Junayd al-Eskafi - Abu Ali Muhammad b. AhmedIbn al-Junayd al-Eskafi was one of the early pioneers of Twelver Shi‘ism and was one of the teachers of al-Shaykh al-Mufīd in Baghdad. He excelled in Fiqh and Usul, and was a pioneer in these sciences, laying much of the ground work for later Shi’a Jurists. He was also renowned for his abilities in theology and Hadith studies.
Al-Kulayni Muhammed b. Yaqub - Abu Ja'far Muhammadb. Yaqubb. Ishaq al-Kulayni Al-Razi (864AH/941AD) was one of the leading hadith compilers in the Twelver Shi‘a tradition. Al-Kulayni is the author of “Kitab al-Kafi,” which is one of the four central books of Shi’a ‘a traditions attributed to the Shi’a. Al-Kulayni lived during the era of the Minor Occultation of the Twelfth Imam (a.s). He is originally from Rey, near present day Tehran.
Al-Shaykh al-Saduq - Al-Shaykh al-Saduq (d. 991 CE) is the title given to Abu Jafar Muhammad b. Ali b. Babawayh al-Qummi. He was the leading traditionalist of his time and one of the most outstanding traditionalists of Shi’a Islam. He earned the title of al-Shaykh al-Saduq on account of his great learning and reputation for truthfulness. Al-Saduq wrote important works in Hadith, Doctrinal Theology, and Islamic Law.
Al-Mufid, Muhammed b. Nuʽman - Abu Abd Allah Muhammadb. Muhammad b. al-Numan al-Ukbari al-Baghdadi known as al-Shaykh al-Mufīd (c. 948AH-1022AD) was an eminent theologian, jurist, and historian. He lived during the rule of the Buyid dynasty, which was known for its Shi‘a tendencies. Al-MufId wrote a number of important works in Hadith, History, Islamic Theology, Islamic Law, Shi‘a Apologetics, and Principles of Jurisprudence.
Al-Shaykh al-Tusi, Abu Jaʽfar - Abu Jafar Muhammad b. Hasan Tusi (d. 1068 CE), known as Shaykh al-Taifah (Leader of the School) was a prominent Persian scholar of the Shi’a Twelver tradition. Abu Jafar Muhammad b. Hasan Tusi was a polymath who wrote works in every discipline. His most important works are in the areas of Usul, Fiqh, Historiography, Tafsir, Hadith Science, and Theology. He also compiled two of the four central books of Hadith.
Al-Sharifal-Murtada - Abu al-Qasim Alib Husayn al-Sharif al-Murtada (d.1044 CE) was one of the greatest scholars of his time and was one of the students of al-Shaykh al-MufId. He was the elder brother of Al-Sharif al-Radi, the compiler of Nahjul Balagha. He lived during the era of the Buyid dynasty. Al-Murtada wrote important works in principles of jurisprudence and theology, the latter being of particular importance to Shi‘a Doctrinal Theology.
Al-Muhaqiq al-Hilli - Abu l-Qasim Jafar b al-Hasan al-Hilli was the maternal uncle of Allama Hilli and one of the founders of the School of Hilla in the mid-Euphrates region of Iraq. His contemporaries gave him the title al-Muhaqiq (A scrupulous scholar). Al-Hilli taught jurisprudence and principles of jurisprudence to many learned scholars. It is said that over 400 jurists graduated from his classes. He revived the science of Usul and re-formulated many of its axiomatic principles. He passed away in 1277 CE.
Al-Hilli, Jamal al-Din Hasan - Jamal al-Din Hasan ibn Yusuf ibn 'Ali ibn Muthahhar (d.1325 CE) also known as al-Allamah al-Hilli (The erudite Hilli) was a Twelver Shi‘a theologian and Mujtahid. He was one of the greatest Muslim jurists and scholars of his time. Al-Allamah al-Hilli wrote a number of works covering numerous Islamic sciences. His most important works are in the area of Usul, Fiqh, History of Islamic Law, and Doctrinal Theology.
Fakhr al-Muhaqqin al-Hilli - Al-Shaykh Abu Talib Muhammad b al-Hassan b. Yusuf b. al-Mutahhar al-Hilli was an erudite scholar and son of Al-Allamah al-Hilli. He, like his father, made significant intellectual advancements in the science of Usul al-Fiqh. He was one of the teachers of al-Shahid al-Awwal.
Tusi, Nasir al-Din - Khawaja Muhammad ibn Muhammad ibn Hasan Tusi (1201AH/1274AD), better known as Nasir al-Din al-Tusi, was a Persian polymath and prolific writer. He was also an astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and jurist. He was of the Ismaili tradition but subsequently converted to Twelver Shi‘ism. The Muslim scholar Ibn Khaldun (1332AH–1406AD) considered NasIr al-DIn al-Tusi to be the greatest of the later Persian scholars. Nasir al-Din al-Tusi excelled in a number of Islamic sciences. He wrote books in Shi’a theology, logic, philosophy, astronomy, and mathematics. He also wrote essays on chemistry and physics.
Al-Fadil al-Tuni - Al-Shaykh Abd Allah b. Muhammad al-Tunu al-Bashrawi al-Radawi is the author of the famous Usul work ‘’al-Wafi’’. He excelled in the science of Usul al-Fiqh and Fiqh. He is thought to have played an influential role on later jurists and Marja Shaykh Murtada Ansari. He died in 1661 CE
Al-Shahid al- Awwal - Abu Abd Allah Muhammad b. Makki al-Amilian was a Lebanese scholar from the Jabal Amil region. He mastered Usul and Fiqh at a young age and authored works in these areas of learning. His scholarly brilliance led to his imprisonment by the Ottoman authorities. He died in prison in the year 1384 CE after his arrest.
Al-Shahid al-Thani - Al-Shaykh Zayn al-Din b. Ali al-Jubai al-Amili was an itinerant Jurist who laid the foundation for modern Fiqh. He authored over 20 works, most of which were on Fiqh. He died in the year 1558 CE.
Al-Amili, Hur - Muhammad b al-Hasan b. Ali b. al-Husayn al-Amili, commonly known as Al-Hurr Al-Amili (1624AH -1693 CE), was a Muhaddith and a prominent Twelver Shi’a scholar of the Akhbari school of law. He is best known for his comprehensive Hadith compilation known as 'Wasail al-Shia'. He also wrote works on the Qur’an, biographical studies, dogmatic theology, and divine miracles.
Al-Majlisi, Muhammed Baqir - Muhammad Baqir Majlisi (1616AH–1698 CE) was a renowned and very influential Twelver Shi’a cleric, during the Safavid era. Muhammad Baqir MajlIsi wrote important works in Hadith, most notably 'Bihar al-Anwar', History and Shi’a Apologetics.
Al-Wahid al-Behbahani - Muhammad b. Baqir b. al-Mawla Muhammad b. Akmal was the founder of modern Shi'a Usul. He revived the science’s principles and led a prolific career as a teacher, Jurist, and thinker. He lived and taught in Karbala, Iraq, at a time when the city was known as the centre of Shi’a learning.
Al-Bahrani, Yusuf - Yusuf b. Ahmed al-Bahrani (1695AH-1772 CE) was a Bahraini theologian and a key figure in the intellectual development of Twelver Shi’a Islam. He grew up in Safavid-ruled Bahrain, at a time of intellectual ferment between Akhbari and Usuli Shi’a. His family were Usuli clerics who also worked as pearl merchants. Yusuf b. Ahmed al-Bahrani wrote important works in biographical studies and Hadith collection.
Sayyid Mahdi Bahr al-Ulum - Al-Sayyid Muhammad Mahdi b. al-Sayyid Murtada b. Muhammad Bahr al-Ulum al-Tabatabai was an erudite scholar and perhaps one of the last polymaths in the modern period. He had a prolific career and authored a number of works in Usul, Fiqh, Rijal, Hadith, Philosophy, History, and Mysticism. He is also famous for his inter-faith debates with the Jews and Christians of Iraq. He passed away in 1797 CE.
Kashif al-Ghita - Al-Shaykh Jafar Kashif al-Ghita was one of the last polymaths in the modern period. He is best known for his work “Kashf al-ghita''. He led an active scholarly life by writing a number of important works in Usul and Fiqh. He also led activist campaigns against colonialism and imperialism in the Middle East. He passed away in 1813 CE
Sahib al-Jawahir - Al-Shaykh Muhammad Hassan b al-Shaykh Baqir b. Abd al-Rahim al-Najafī revived seminary studies in Najaf after a period where most scholarly activity took place in Karbala. His students, such as Murtada Ansari, played an influential role in shaping the modern syllabi of the Najaf seminary. Al-Jawahiri is most famous for his work "Jawahir al-kalam fisharhsharai al-islam." He passed away in 1850 CE.
Shaykh Murtada Ansari - Shaykh Murtada Ansari was widely known as the most eminent jurist of recent times. He lived in Najaf and taught classes in Usul and Fiqh. His theories in Usul still remain the main principles upon which jurists of today rely on. He passed away in 1864 CE.