Despite being of the key Shi'i Muslim communities, the Ismailis have generally been studied primarily on the basis of the accounts of their enemies, such as Sunni polemicists and the Crusader chroniclers. This introduction to Ismaili history takes account of recently recovered Ismaili texts. It covers the main developments in the major phases of Ismaili history, from the early formative period, through the Fatimid golden age and the Alamut and post-Alamut periods, to more recent history, and gives a critical analysis of the available source materials.