King of Babylonia. Known as Soter (“Savior”), Demetrius ascends to power after deposing and slaying his nephew Antiochus V and defeating Timarchus, a pretender to the throne. During his reign, he is confronted by a resurgence of the Maccabean Revolt, as well as, a more generalized uprising, led by a son of Antiochus IV, which would end in his defeat. Demetrius I is mentioned in the Babylonian King List of the Hellenistic Period as «Idi».