This volume complements the selections of Wilferd Madelung's articles previously published by Variorum (Religious Schools and Sects in Medieval Islam, and Religious and Ethnic Movements in Medieval Islam). The first articles here examine legal and political aspects of early Shi'ism. The following studies relate to doctrinal views of the Zaydi imams al-Qasim b. Ibrahim al-Rassi and al-Natiq bi-l-Haqq and to Zaydi attitudes to Sufism. The final group focuses on the Isma'iliyya, their social and political history and aspects of their religious thought. A detailed index completes the volume.