Jurist and student of Abu Hanifah and Malik ibn Anas. Trained in jurisprudence of both the Iraqi and Medina schools. Insisted on the decisive role of hadith in Islamic law. Held a high position in the Abbasid court, enabling him to spread the writings and ideas of the Hanafi school. First jurist to write down Hanafi legal thought. Wrote a detailed work on inheritance law and the first comprehensive treatise on the law of jihad. Formulated the doctrine of international law (siyar), helping to rationalize relations with the outside world and discuss the rights of non-Muslims in Islamic law. Supported equality of Muslims and non-Muslims under Islamic law, except in family matters.