Demetrius III Theos Philopator Soter Philometor Euergetes Callinicus was a Hellenistic Seleucid monarch who reigned as the King of Syria between 96 and 87 BC. He was a son of Antiochus VIII and, most likely, his Egyptian wife Tryphaena. Demetrius III's early life was spent in a period of civil war between his father and his uncle Antiochus IX, which ended with the assassination of Antiochus VIII in 96 BC. After the death of their father, Demetrius III took control of Damascus while his brother Seleucus VI prepared for war against Antiochus IX, who occupied the Syrian capital Antioch.

Antiochus VIII Epiphanes/Callinicus/Philometor, nicknamed Grypus, was the ruler of the Hellenistic Seleucid Empire from 125 to 96 BC. He was the younger son of Demetrius II and Cleopatra Thea. He may have spent his early life in Athens and returned to Syria after the deaths of his father and brother Seleucus V. At first he was joint ruler with his mother. Fearing her influence, Antiochus VIII had Cleopatra Thea poisoned in 121 BC.