Alexander is born at Pella in Macedonia, the son of King Philip II and Olympias. His first tutor, Leonidas, teaches Alexander math and military skills, such as archery and horsemanship. He trains Alexander to be physically tough. After a few years Aristotle becomes his tutor and he teaches Alexander to appreciate philosophy, geography, Greek poetry, and scientific investigation. Alexander particularly loves Homer's Iliad, which inspires him to dream of becoming a great warrior.
At age 16, Alexander finishes studying under Aristotle and joins his father's army. By this point, Philip controls all the Greek city-states except Athens and Thebes. He aims to unite the Macedonians and Greeks and invade the Persian Empire. In August 338 BCE, the Macedonians meet the Athenians and Thebans in battle at Chaeronea. Alexander leads the attack against the Thebans, while his father leads the attack against the Athenians. It is Alexander's first taste of battle, and he and his father defeat the Greeks, placing all Greek city-states except Sparta under Macedonian control.
In October 336 BCE, Philip celebrates his upcoming departure to attack Persia, as well as the marriage of his daughter Cleopatra. However, one of his bodyguards assassinates him in the theater of Agae. Alexander becomes king of Macedonia at the age of 20. After Philip's death, the Thracians and Illyrians rise up in rebellion. This inspires the Greek city-state of Thebes to rebel, and Alexander quickly besieges the city and razes it to the ground. The inhabitants are executed or sold into slavery, showing the other city-states that Alexander is just as powerful as his father.
After subduing rebellious Greek city-states, Alexander plans his campaign against the Persians, hoping to fulfill his father's dream of conquering the empire. After crossing the Hellespont, Alexander leads the Macedonian army against the Persians at the Granicus river. After savage fighting, the Persians retreat, and Alexander's army moves across the southern coast of Asia toward Gordium. As they travel, they liberate a number of cities from Persian rule.
Alexander and Darius, king of the Persians, meet at Gaugamela in a decisive battle. Alexander's military skills overwhelm Darius, who orders his men to flee, and the Macedonians are victorious. Alexander moves from one major Persian city to the next, conquering Babylon on October 18, 331 BCE, and taking treasure to distribute among his men.
Later after conquering eastern Iran and capturing Prince Oxyartes, Alexander marries Roxane, the prince's daughter. This is meant to be a political alliance, and it serves as an insult to Barsine, Alexander's Persian mistress. Roxane later bears Alexander a son. A year later, after several months in India, however, Alexander's army refuses to go any farther, and he is forced to return to Babylon. He spends the next few years trying to consolidate power in his empire.
Finally, Before Alexander can set out on his new campaign, he falls ill with a sudden fever. According to legend, he leaves his empire to "the strongest" of his commanders, but after his death, his empire falls into disorder. His three commanders divide up the empire and compete for control.