Shi'i communities in history -- The study of the Ismailis : phases and issues -- Ismaili history and literary traditions -- Idris Imad al-Din and medieval Ismaili historiography -- A major schism in the early Isma'ili movement -- The Ismaili da'wa under the Fatimids -- The concept of ujja in Ismaili thought -- Cyclical time and sacred history in medieval Ismaili thought -- Ali in classical Ismaili theology -- Al-qadi al-nu'man, Isma'ili law and Imami shi'ism -- The Iranian school of philosophical Ismailism -- The medieval Isma'ilis of the Iranian lands -- The "order of the assassins" : J. von Hammer and the Orientalist misrepresentations of the Nizari Ismailis -- Ismaili-Seljuq relations : conflict and stalemate -- Sinan and the Nizari Ismailis of Syria -- Hidden Imams and Mahdis in Ismaili history -- Religious identity, dissimulation and assimilation : the Ismaili experience