Philip I Philadelphus was the 3rd son of Antiochus VIII Grypus and took the diadem in the 95 BC together with his twin brother Antiochus XI Ephiphanes, after the eldest son Seleucus VI Epiphanes was killed by their cousin Antiochus X Eusebes. He managed to establish himself in Antiochia sometime after 92 BC and survived attacks from younger brother Demetrius III Euergetes. His rule was ended in 83 BC when Tigranes conquered Syria, or sometime before, and he disappears from history at that point, but later coins bearing his portrait were issued by the Roman authorities.