Book excerpt: Ahmed El Shamsy's The Canonization of Islamic Law is a detailed history of the birth of classical Islamic law. It shows how Islamic law and its institutions emerged out of the canonization of the sacred sources of Quran and Sunna (prophetic practice) in the eighth and ninth centuries CE. The book focuses on the ideas and influence of the jurist al-Shāfiʿī (d. 820 CE), who inaugurated the process of canonization, and it paints a rich picture of the intellectual engagements, political turbulence, and social changes that formed the context of his and his followers' careers.