Abu Ishaq al-Shirazi

Abu Ishaq Ibrahim ibn 'Ali al-Shirazi (393–476 AH / 1003–1083 CE) was a leading jurist of the Shafi'i school — one of Sunni Islam's four schools of law (madhhab) — and a master of usul al-fiqh, the theory of how law is derived from the Qur'an and the Prophetic tradition. Born in Firuzabad in the Persian region of Fars, he is reported to have studied first in his hometown, then in Shiraz and Basra, before settling in Baghdad, where his principal teacher was the Shafi'i jurist Abu al-Tayyib al-Tabari. Sources disagree on the exact year of his arrival in Baghdad: some give 410 AH (c. 1019 CE) and others 415 AH (c. 1024 CE).

He spent the rest of his life in Baghdad as a teacher, mufti (jurist who issues legal opinions), and renowned debater. When the Saljuq vizier Nizam al-Mulk founded the Nizamiyya college of Baghdad (opened 1067), al-Shirazi was his designated first head; sources report that he did not appear at the inauguration — reportedly in protest at the demolition of Baghdad houses for building materials — so that Ibn al-Sabbagh taught there first, and al-Shirazi only took up the chair afterward (his inaugural lecture is dated 13 October 1067). He is remembered as the school's long-serving and most celebrated early professor.

His textbooks shaped Shafi'i learning for centuries: al-Muhadhdhab and al-Tanbih (practical law), al-Luma' and al-Tabsira (legal theory), and Tabaqat al-Fuqaha', an early biographical dictionary of jurists. In theology he is generally counted among the Ash'aris, though the precise extent of his involvement was discussed by later writers. He died in Baghdad in 476 AH (1083 CE); the 'Abbasid caliph al-Muqtadi is reported to have attended his funeral, a mark of unusual honor.