It is with great sadness that we note the death of our friend and colleague, noted scholar Professor Wilferd Madelung (1930-2023). In this special event at IIS on 18 July 2023, colleagues paid tribute to him and shared their personal reflections. During his academic career, spanning more than 65 years, Professor Madelung made major contributions to many aspects of early and medieval Muslim history and thought. With particular reference to religious schools and movements in early Islam, his studies, based on a vast array of primary sources, have enriched the discipline’s understanding of almost every major Muslim movement and community – not only early Imami Shi‘ism and the later developments of Twelver, Ismaili and Zaydi Islam but also the lesser known aspects of Sunni, Khariji and the Mu‘tazili schools of theology and philosophy.