Battle of Antioch
The Battle of Antioch (145 BCE), also known as the Battle of the Oenoparus was a conflict between the Ptolemaic Kingdom and the Seleucid Empire as part of the Syrian Wars. During this battle the Seleucid king Alexander Balas was defeated by Ptolemy VI Philometer who would also himself perish in the battle. Alexander Balas would become king of both Coele-Syria and Pergamon in 150 BCE following his victory over Demetrius I Soter which would be all that remained of the once mighty Seleucid Empire as established by the founder Seleucus I Nicator which had stretched as far as India.
In the beginning Alexander Balas would have the support of Ptolemy VI Philometer and was married to his daughter named Cleopatra Thea. However, after he was successful in gaining the Seleucid throne he began to engage more in the materialistic aspects of life rather than maintaining his crumbling empire. Following this Demetrius II Nicator who was the son of Demetrius I Soter would exploit this weakness and return to Syria and seek out the support of Ptolemy VI. He would be successful and eventually abandon Alexander Balas in 148 BCE and marry Cleopatra Thea to Demetrius II.
Alexander Balas was obviously not pleased about the new arrangement and the Battle of Antioch is what followed. The conflict occurred outside of the city of Antioch between the forces of Ptolemy and Demetrius II against Balas who was eventually defeated. Ptolemy VII would suffer a mortal wound during the engagement and die, leaving the Ptolemaic Kingdom to Ptolemy VII Neos Philopater. Alexander Balas would manage to flee to nearby Nabataea but he would be killed by a local prince who sought favor with the new Hellenistic kings.