Ibn Tulun's power soon made him a major rival to the effective ruler of the Abbasid state, al-Mu'tamid's brother and regent al-Muwaffaq, and in 877 the latter sent an army on an abortive campaign to oust Ibn Tulun from Egypt. In the following year Ibn Tulun extralegally seized control of Syria and other territories up to the border zone with the Byzantine Empire, creating further conflict with the Abbasid regent, and an unsuccessful attempt in 882 by al-Mu'tamid to escape from his brother's control by fleeing to the court of Ibn Tulun caused a complete breach in relations.[2] In the aftermath of the caliph's flight, al-Muwaffaq ordered that Ibn Tulun be publicly cursed in mosques throughout the empire and de jure dismissed him from his governorships, while Ibn Tulun similarly had al-Muwaffaq publicly cursed, declared him deposed from his position as al-Mu'tamid's second heir and proclaimed a "holy war" against him.[3]