In 827, Isa participated in Abdallah ibn Tahir's reconquest of Egypt,[8] which brought an end to the turmoil that had plagued that country since the outbreak of the civil war.[9] After Egypt was pacified and Abdallah departed in 827, Isa was appointed as his deputy governor of the province. When the caliph's brother Abu Ishaq (the future caliph al-Mu'tasim, r. 833–842) took Abdallah's place and assumed the governorship of Egypt in 828, he confirmed Isa as resident governor over the security and prayers.