Title: Viziership in the last periods of the Abbasid state (H. 512-656)

This study deals with the Viziership Institution (H. 512-656) in the Last Periods of the Abbasid State. During the Seljuk period, the vizierate weakened considerably. In fact, we can say that the status of the vizierate depends on the Caliph. When the authority of the caliph strengthened, the vizierate also became stronger. In this study, we revealed the role of the vizier in the administration. As we mentioned in the preface, we discussed the subject in four parts. This study revealed that the office of vizier in the Abbasid State was quite good and powerful thanks to the administrative, military and economic reforms made by the caliphs after 512 H. Likewise, after the caliphate gained its independence after 575 H., it also revealed that the vizierate revived and regained its former power after the caliphate made reforms and took over its former power. In order to deal with the events more comprehensively and to establish the connection between the events, the study includes very detailed information about the lives of the viziers by discussing in detail the relations of the viziers with the caliphs, statesmen and enemies.