Ismailism developed an understanding of Islam and promoted it through an active missionary system. Although the early history remains obscure, Ismailism incorporated elements of Gnosticism, Neoplatonism, and Hindu thought to explain its concept of the imam. Over time it came to stress the importance of the esoteric aspects of the faith over the exoteric. The first success of the Ismaili movement was the establishment of the Qarmat state (see Karmathians) in E Arabia. Ismaili missionaries and its political organization also mobilized a network of N African tribes to support the Fatimid claim to the caliphate in Egypt and several regions of the Mediterranean. An offshoot, the Assassins, established a state in NE Iran, which survived until the 13th cent. In 1094 the Ismailis split into Nizaris and Mustalis. Today, though a minority community that is not politically active, the Ismailis are spread in small pockets in parts of the Middle East, central and S Asia, and increasingly North America and Europe. The family of the Aga Khan, the Nizari imam, traces its descent from Ismail.
See S. M. Stern, Studies in Early Ismailism (1983); F. Daftary, The Ismailis (1990).