King of Macedon 359-336 BCE; father of Alexander the Great by Olympias of Epirus. Argead royal house, claiming Heraclid descent through Caranus. Held as Theban hostage 368-365 BCE in his youth; observed Epaminondas's reformed tactics that became the foundation of his own military reforms. Reformed the Macedonian phalanx (sarissa-armed pike-formation), Companion Cavalry (Hetairoi), and siege-engineering corps — the military system that enabled Alexander's subsequent conquests. Married Olympias of Epirus c. 357 BCE; Alexander born 21 July 356 BCE; Cleopatra of Macedon born c. 355 BCE. Defeated the Athens-Thebes coalition at Chaeronea (August 338 BCE); established the League of Corinth (337 BCE) as hegemon; began preparations for the Persian invasion that Alexander would execute. Married Cleopatra Eurydice in 337 BCE — the marriage that estranged Olympias and produced the wedding-banquet Attalus-toast scandal. Assassinated October 336 BCE at the wedding of his daughter Cleopatra of Macedon to Alexander I of Epirus, in the theater at Aegae, by his own bodyguard Pausanias of Orestis. Buried at Aegae (modern Vergina); Tomb II of the Vergina royal tombs (Andronikos 1977-1978) widely identified as his. Under the Mongán-pattern dual-paternity classification of Alexander, Philip is recorded as social-father with Zeus-Ammon as paternal deity per the Siwa Oracle 332 BCE recognition.