Philippos, Philip II of Macedon, ruled Macedon as king and was Alexander's father. His marriage to Olympias produced Alexander, though mutual distrust fractured their bond, fueled by Olympias's assertion that Zeus, not Philip, fathered Alexander. Philip demonstrated violent tendencies, especially when drunk, including an attempt to rape Olympias witnessed by the young Alexander.

Philip secured Aristotle as Alexander's tutor, focusing his education on philosophy, warfare, and leadership. He voiced pride in Alexander's potential but also subjected him to harsh criticism, publicly mocking Alexander's reserved nature during feasts. Philip's military innovations forged the Macedonian army into a formidable, professional force, creating the instrument Alexander later wielded for conquest.

His marriage to Eurydice, niece of Attalus, ignited a political crisis. At the wedding celebration, Attalus proclaimed Eurydice's future sons as legitimate heirs, prompting Alexander to disown Attalus as kin. An intoxicated Philip drew his sword against Alexander before exiling him from court.

Philip was assassinated in 336 BC during public games celebrating the wedding. While Alexander suspected Olympias's involvement, historical accounts cited in the film identify Pausanias, a disgruntled guardsman, as the assassin who stabbed Philip. His death thrust Alexander onto the throne, leading Alexander to order the executions of Attalus, Eurydice, and their infant son to secure his rule.

Philip's legacy haunted Alexander's campaigns. Alexander strove to surpass his father's achievements while wrestling with Philip's disparaging remarks about his capabilities. Philip's descent into drunken violence served as Alexander's cautionary tale about power's corrupting nature.