Cataloged from PDF version of article. Thesis (Ph.D.): Bilkent University, Department of History, İhsan Doğramacı Bilkent University, 2022. Includes bibliographical references (leaves 308-368). The objective of this study is to analyze the socio-political causes and effects of the turmoil in the Crimean Khanate (1623-1628) depending mainly on the Crimean Tatar, Ottoman, Polish, Russian, Romanian, and Persian sources The Karaçi system, inherited from the Golden Horde, that forced the Khans to share the power with the Karaçi leaders was the major obstacle for the stability of the Khan. The Ottomans were depending on the cooperation of the Karaçi leaders and their superior fire arms in order to keep the Khans under control. Mehmed Giray III Khan and Kalgay Şahin Giray Sultan brothers who realized this fact put the Karaçi leaders under strict control and made an alliance with the Zaporozhian Cossacks who were effectively using fire arms and defeated the Ottomans. Consequently, they have managed to remain in the power for five more years, contrary to the Ottoman’s plan to replace them with Canıbek Giray Khan and Devlet Giray Sultan. by Ahmet Türk Ph.D.