Demetrius III Eucaerus

Demetrius III Theos Philopator Soter Philometor Euergetes Callinicus (Ancient Greek: Δημήτριος θεός Φιλοπάτωρ σωτήρ Φιλομήτωρ Εὐεργέτης Καλλίνικος, surnamed Eucaerus; between 124 and 109 BC – after 87 BC) was a Seleucid monarch who reigned as the King of Syria between 96 and 87 BC. The son of Antiochus VIII, he took control of Damascus after his father's murder while his brother Seleucus VI prepared for war against their father's half-brother and rival, Antiochus IX, who occupied the Syrian capital Antioch.

The civil war dragged on; Seleucus VI eliminated his uncle, whose heir Antiochus X counterattacked and drove Seleucus VI to his death. Then the twins Antiochus XI and Philip I, brothers of Demetrius III, attempted to avenge Seleucus VI; it ended with the death of Antiochus XI and the interference of Demetrius III on the side of Philip I in a war against Antiochus X that probably lasted until 88 BC. In 89 BC, Demetrius III invaded Judaea and crushed the forces of its king, Alexander Jannaeus; his near victory was cut short by the death of Antiochus X. Demetrius III rushed to Antioch before Philip I could take advantage of the power vacuum and strengthen his position relative to Demetrius III.

By 87 BC, Demetrius III had most of Syria under his authority. He attempted to appease the public by promoting the importance of the local Semitic gods, and he may have given Damascus the dynastic name Demetrias. By late 87 BC, Demetrius III attacked Philip I in the city of Beroea, where Philip I's allies called on the Parthians for help. The allied forces routed Demetrius III and besieged him in his camp; he was forced to surrender and spent the rest of his life in exile in Parthia. Philip I took Antioch, while Antiochus XII, another brother of Demetrius III, took Damascus.

Source: Wikipedia — https://en.wikipedia.org/wiki/Demetrius_III_Eucaerus