al-Muhaqqiq al-Hilli

Najm al-Din Ja'far ibn al-Hasan, known by the honorary title al-Muhaqqiq ("the verifying scholar") al-Hilli, was a Twelver Shi'i jurist born around 602 AH / 1205 CE in Hilla, a town in central Iraq that had become a leading center of Twelver Shi'i learning. He is also called al-Muhaqqiq al-Awwal ("the First Muhaqqiq") to distinguish him from later scholars given the same title.

He came from a family of prominent Shi'i jurists and, according to the biographical tradition, studied first with his father and then with other scholars of Hilla, where he spent essentially his entire life teaching and writing. He worked within the Ja'fari school — the legal tradition (madhhab) followed by Twelver Shi'a — and is remembered for systematizing its fiqh (jurisprudence).

His most influential book, Shara'i al-Islam fi masa'il al-halal wa-l-haram ("The Laws of Islam"), organized Twelver law in a concise four-part scheme that later jurists adopted as a standard framework; tradition counts dozens of commentaries written on it. He also wrote Ma'arij al-usul on legal theory and al-Mu'tabar and al-Nafi' on substantive law.

He taught the next generation of Hilla's scholars, including his nephew and student al-Allama al-Hilli. Reports describe the philosopher and statesman Nasir al-Din al-Tusi visiting Hilla as a representative of the Mongol Ilkhanid ruler Hulagu and acknowledging al-Muhaqqiq as the town's leading scholar. He died on 13 Rabi' I 676 AH / 14 August 1277 CE in Hilla, where he was buried.