The rise of the Buwayhids to power during the fourth century of the Hijra is important in the history of medieval Islam not only from political but also from cultural, administrative and religious standpoints, all of which form the subject matter of the present study. Despite the importance of the subject the only study of the Buwayhids, apart from general histories such as Muller's Per Islam in Morgen-und Abendland and works such as Levy's Baghdad Chronicle, Mez's Renaissance of Islam and Minorsky's La Domination des Dailamites, is Said Hasan's History of the Early Buwayhids, which, however, deals only with the foundation of the dynasty down to the death of Mu'izz al-Dawla in 356 A.H. It is chiefly on this account that this study deals with the fortunes of the rest of the Buwayhids of Baghdad, from the accession of Mu'izz al-Dawla's son in that year down to the overthrow of al-Malik al-Rahim in 447 A.H.; and it is hoped that, providing as it does a more detailed examination of all the available sources, chiefly Arabic, than has yet been made, it may shed new light on this later and much longer period. Beginning with an introduction which summarises the rise of the Buwayhids, the first five chapters aim at the reconstruction of the political history together with an account of the development of art and learning under the individual rulers. In the next three chapters a study of the administrative institutions has been attempted. Finally the last two chapters discuss respectively the relationship of the Amirs to the Abbasid Caliphs and the religious background to the rise and fall of the dynasty.