Ishoʿyahb II of Gdala was Patriarch of the Church of the East from 628 to 645. He reigned during a period of great upheaval in the Sasanian Empire. He became patriarch at the end of a disastrous war between Rome and Persia, which weakened both powers. Two years later the Moslem Arabs began a career of conquest in which they overthrew the Sassanian empire and occupied the eastern provinces of the Roman empire. Ishoʿyahb lived through this momentous period, and is said to have met both the Roman emperor Heraclius and the second Moslem caliph ʿUmar ibn al-Khattab.