سلسلة جبال لبنان الشرقية
With full autonomy, once the tax income no longer had to go to the Caliph in Baghdad, it was possible to develop irrigation works and build a navy, which greatly stimulated the local economy and trade. In 878, the Jordan valley was occupied by the Tulunids, extending in the north to the outposts in the Anti-Lebanon mountains on the Byzantine border, enabling them to defend Egypt against Abbasid attack.