al-Qadi al-Nu'man

Al-Qadi al-Nu'man ibn Muhammad (c. 290 AH/903 CE – 363 AH/974 CE) was the principal jurist of the early Fatimid state and the founder of Ismaili Shia jurisprudence (fiqh, Islamic law). He was born into a learned family in Kairouan, in Ifriqiya (roughly modern Tunisia). His religious background before he became an Ismaili is debated by scholars: some hold he was first a Maliki or Hanafi Sunni, others that his outlook was Ismaili from early on; the sources do not settle it.

He entered Fatimid service around 313 AH/925 CE under the dynasty's founder, the imam-caliph Abdullah al-Mahdi, and served the first four Fatimid imam-caliphs over roughly half a century. He held a series of posts — keeper of the palace library and judge in Tripoli and in the capital al-Mansuriyya — before being appointed chief judge (qadi al-qudat) in 337 AH/948 CE. The caliph al-Mu'izz confirmed him and entrusted him with hearing grievances (mazalim).

His most influential work, Da'a'im al-Islam ("The Pillars of Islam"), produced under al-Mu'izz's supervision, became the official legal code of the Fatimid empire and remains authoritative for Tayyibi Ismailis today. He also wrote on history, scriptural interpretation, and the inner (esoteric) meanings of the law.

In 362 AH/973 CE he accompanied al-Mu'izz to the newly founded Egyptian capital, Cairo, where he died. Reports place his death on the last day of Jumada II 363 AH (27 March 974 CE); it is traditionally held that the caliph himself led his funeral prayer.