Antiochus (/ænˈtaɪ.əkəs/; Greek:Ἀντίoχoς; killed c. 226 BC), called Hierax (/ˈhaɪəræks/, Ἱέραξ, "Hawk") for his grasping and ambitious character, was the younger son of Antiochus II and Laodice I and separatist leader in the Hellenistic Seleucid kingdom, who ruled as king of Syria during his brother's reign.