Palestine, he appointed a Christian as governor of Jerusalem, and possibly even of the provincial capital, Ramla, thereby putting an end to the persecution of Christians and allowing the renovation of churches. Expansion into Syria In the early 870s, a major change took place in the Abbasid government, as the Abbasid prince al-Muwaffaq emerged as the de facto regent of the empire, sidelining his brother, Caliph al-Mu'tamid (r. 870–892). Officially, al-Muwaffaq controlled the eastern half of the Caliphate, while al-Mu'tamid's son and first heir al-Mufawwad controlled the western, with the aid of the Turkish general Musa ibn Bugha. In reality al-Muwaffaq held the actual reins of power. Al-Muwaffaq however was preoccupied with the more immediate threats to the Abbasid government presented by the rise of the Saffarids in the east and by the Zanj Rebellion in Iraq itself, as well as with keeping in check the Turkish troops and managing the internal tensions of the caliphal government. This gave Ibn Tulun the necessary space to consolidate his own position in Egypt. Ibn Tulun kept himself out of the Zanj conflict, and even refused to recognize al-Mufawwad as his suzerain, who in turn did not confirm him in his position. Open conflict between Ibn Tulun and al-Muwaffaq broke out in 875/6, on the occasion of a large remittance of revenue to the central government. Counting on the rivalry between the Caliph and his over-mighty brother to maintain his own position, Ibn Tulun forwarded a larger share of the taxes to al-Mu'tamid instead of al-Muwaffaq: 2.2 million dinars went to the Caliph and only 1.2 million dinars to his brother. Al-Muwaffaq, who in his fight against the Zanj considered himself entitled to the major share of the provincial revenues, was angered by this, and by the implied machinations between Ibn Tulun and his brother. Al-Muwaffaq sought a volunteer to replace him, but all the officials in Baghdad had been bought off by Ibn Tulun and refused. Al-Muwaffaq sent a letter to the Egyptian ruler demanding his resignation, which the latter predictably refused. Both sides geared for war. Ibn Tulun created a fleet and fortified his borders and ports, including Alexandria, and a new fortress on Rawda Island to protect Fustat. Al-Muwaffaq nominated Musa ibn Bugha as governor of Egypt and sent him with troops to Syria. In the event, due to a combination of lack of pay and supplies for the troops,