I.B. Tauris in association with the Institute of Ismaili StudiesThe Tathbit al-imama attributed to the Fatimid Caliph-imam al-Manur (334–341/946–953) is animportant early Ismaili treatise on the legitimacy of the imamate of Ali b. Abi Talib and that of the Ismailiimams from among his progeny. As one of the earliest Ismaili works on this crucial and fundamental Shi'isubject it can thus be considered a major treatise on the doctrine of the imamate.The Tathbit al-imama does not deal with the metaphysical significance of the imamate. rather, itconcentrates on its legal and historical aspects, using proofs derived from the Quran, Hadith and logicalarguments. in this regard, it is directed at the Islamic public in all its different religious affiliations.in the way it discusses the necessity of the imamate itself, the right of the imams to the viceregency of the Prophet, and the validity of divine designation in contrast to election by the umma, it is likely that theTathbi al-imama could have also meant to serve as a guide book for the Ismailis in legitimizing the Alidstate ruled by the Fatimid Caliph-imams. This edition has been compiled from two manuscriptsof the Tathbit, both of which are now in the collections of the library of The Institute of Ismaili Studies, withthe Arabic text carefully translated into idiomatic English to retain the character and flavour of theoriginal text as much as possible.