The Battle of Gaugamela took place on October 1, 331 BC, and marked the decisive confrontation between Alexander the Great of Macedon and King Darius III of Persia. Following this victory, Alexander became the ruler of Asia.
Prelude to Gaugamela
After the assassination of his father, Philip II, in 336 BC, Alexander the Great left Macedonia to conquer Persia. Throughout his campaign, King Darius III and his generals consistently underestimated the young Macedonian, viewing him as nothing more than an ambitious upstart. After over a year of preparation, Alexander met Darius in battle at Issus in November 333 BC, inflicting a humiliating defeat on the Persians. This time, Alexander captured Darius’ mother, wife, and daughters. Desperate to avoid further losses and regain his family, Darius offered half of his kingdom to Alexander and his daughter’s hand in marriage. However, the latter dismissed the proposal, insisting that having two rulers would disrupt the natural order, and he challenged Darius to face him once more on the battlefield.
From Issus, Alexander pushed down the Mediterranean coast, capturing the fortified island city of Tyre. His campaign continued southward, where he was welcomed in Jerusalem and Egypt, both of which had suffered under Persian rule. In Egypt, he laid the foundations for the future city of Alexandria before preparing for his next confrontation with Darius.
Alexander originally planned to march directly to Babylon, but upon learning of Darius’ position at Gaugamela, he shifted course northward to confront the Persian king. He knew that a decisive victory there would secure the heart of the Persian Empire—Babylon, Persepolis, and Susa.
Darius, having learned from his defeat at Issus, carefully selected Gaugamela for their next encounter. Estimates of his forces range from 50,000 to as many as a million. The battlefield at Gaugamela, with its broad plains, was chosen to allow him to deploy his cavalry and chariots effectively. He even had the terrain levelled and set traps to hinder Alexander’s advancing forces. Confident in the size of his army and the favourable terrain, Darius believed he held a significant upper hand.
Alexander made camp several miles away, with his 40,000 troops bringing only their weapons for battle. After assembling a small scouting party, he secretly surveyed Darius’ preparations from a hill and captured members of a Persian advance guard, who revealed information about Darius’ numbers and the traps awaiting them on the battlefield. The night before the battle, Alexander convened a council of his generals. Parmenio, his commander on the left flank, advised launching a surprise night attack, arguing that it would catch Darius’ forces off guard. However, Alexander rejected this strategy, believing it would be dishonourable.
The Battle
On the day of the battle, Alexander reportedly overslept. As with previous battles, he ensured his troops were well-fed and well-rested, while Darius’ army had stayed awake all night, anxious about a night attack that never came. As Alexander surveyed the Persian forces, he called out to his soldiers, praising their bravery and encouraging them to fight once again for Macedonia. At that moment, an eagle—Zeus’ sacred bird—flew overhead in the direction of Darius, which he took as another divine omen of victory.
As the battle began, Alexander and his Companion Cavalry positioned themselves on the right flank, while Parmenio commanded the left. In the centre stood the Macedonian phalanx, supported by light infantry and archers on both sides. Anticipating a flanking attempt by the Persians, Alexander made a tactical adjustment, positioning infantry at angled formations on the ends of both flanks and additional Greek infantry behind the centre for extra defence.
When the fighting commenced, Alexander and his Companions advanced obliquely to the right, prompting the Persians to shift left to outflank them. This manoeuvre stretched the Persian line into uncleared terrain, creating a gap in their formation. Spotting the opening, Alexander swiftly formed his men into a wedge and charged directly toward the unprepared Darius. Meanwhile, Darius sent his scythed chariots against the Macedonian centre. However, this proved ineffective, as the Macedonian phalanx opened its ranks, allowing the chariots to pass through without inflicting significant damage. The Persian charioteers were quickly overwhelmed by the Macedonian infantry, and intense hand-to-hand combat ensued.
On the right, Alexander saw his chance and hurled a spear at Darius, narrowly missing the Persian king. Realising that the battle was lost, Darius fled, just as he had done at Issus. With their king in retreat, the Persian left flank lost morale and quickly collapsed, leading to Alexander’s victory.
Aftermath
The Battle of Gaugamela was a catastrophic defeat for the Persians and one of Alexander’s most remarkable victories. Darius managed to escape with a small contingent of his forces still intact. He planned to raise a new army to confront Alexander, and sent letters to his eastern satraps, urging them to remain loyal. However, Bessus, a Persian satrap of the eastern Achaemenid satrapy of Bactria, betrayed and murdered Darius before fleeing eastward. When Alexander learned of his murder, he honoured him with a full burial ceremony at Persepolis, the former ceremonial capital of the Persian Empire, and pursued Bessus, capturing and executing him the following year.
With Darius dead, most of the remaining Persian satraps pledged their loyalty to Alexander, who allowed them to retain their positions. The death of Darius is traditionally seen as marking the end of the Achaemenid Persian Empire.
