The Sunni revival is the thread that weaves through the tapestry of Yasser Tabbaa's The Transformation of Islamic Art During the Sunni Revival. He defines the Sunni revival as "the theological and political movement that sought to reaffirm traditionalist Islam and reject rationalist thought while declaring allegiance to the Abbasid caliphate and opposing all its enemies". The political and theological movement towards a reestablishment of Abbasid power through Sunni unity is known as the Sunni revival. The Qadiri Creed became the official dogma of the Abbasid caliphate in the first half of the eleventh century and formed the theological cornerstone of the Sunni revival. The Transformation of Islamic Art examines how the theological tenets and political conflicts that developed during the Sunni revival influenced the art and architecture of the medieval period. As Tabbaa explains, during the Sunni revival, the Abbasids began to use cursive scripts instead of the old angular kufic script to copy Qur'an manuscripts and inscriptions.