During the caliphates of al-Mahdi (r. 775–785), Harun al-Rashid (r. 786–809), and al-Amin (r. 809–813) Ishaq was posted to various provinces throughout the empire. In 776/7 he was appointed as governor of Mosul,[6] and in 786–787 he was in charge of Medina.[7] According to some sources he oversaw the summer raid (sa'ifa) against the Byzantines in 787/8 or 788/9, either leading it himself or dispatching Yazid ibn Anbasah al-Harashi to conduct it on his behalf.[8] In 790/1 he was governor of Sind and Makran.[9]