This is an annotated English translation of Qadi al-Nu'man's Iftitah al-de' wa. This book is the most important primary source for the emergence of the Fatimid state in the early years of the tenth century. Its author, Qadi al-Nu'man, was an official historian of the Fatimids and an eminent exponent of Ismaili jurisprudence--as well being perhaps the most distinguished and creative of all the Fatimid thinkers. The Iftitah is al-Nu'man's major historical work, and records in detail the background to the establishment of the Fatimid state, first in Yemen and then in north...