The Fatimid period was the golden age of Ismaili thought and literature, when the Shi'ite Ismaili Imams ruled over the vast areas of the Muslim world as the Fatimid caliphs and the Ismailis made important contributions to Islamic civilization. In this book, Heinz Halm investigates the intellectual traditions that developed among the Ismailis from the rise of the Fatimid state in North Africa to the cultural brilliance of what the author calls 'one of the great eras in Egyptian history and in Islamic history in general.'