The Battle of Gaugamela: The End of the Persian Empire
The Battle of Gaugamela, fought on 1 October 331 BCE on the broad plain of Gaugamela in what is now northern Iraq, was the decisive engagement between Alexander the Great and the Persian king Darius III. The battle marked the end of the Persian Empire, the beginning of the Hellenistic age, and the emergence of Alexander as the master of the largest empire the world had ever seen. Alexander’s smaller but more disciplined and more flexible army defeated a much larger Persian force, Darius fled the field, and the Persian Empire collapsed almost immediately. Babylon, Susa, Persepolis, and the other capitals of the empire all surrendered to Alexander without a fight, and within a few years the young Macedonian king had built an empire that stretched from Greece to India.
This page is a complete guide to the Battle of Gaugamela. It explains the strategic background, the battle itself, and the legacy. It links back to the Alexander the Great cluster, the Death of Alexander long-tail, and the Ancient Warfare pillar.
The Strategic Background
The Battle of Gaugamela was the culmination of three years of campaigning. Alexander had crossed into Asia in 334 BCE with an army of about 47,000 men. He had defeated the Persian satraps at the Granicus (334 BCE), won a major victory over Darius himself at Issus (333 BCE), and conquered the eastern Mediterranean coast, including the famous seven-month siege of Tyre. In 332 BCE he had entered Egypt unopposed and been crowned pharaoh. In 331 BCE, after a long campaign through Mesopotamia, he was approaching the heart of the Persian Empire.
The Persian king Darius III, having survived the disaster of Issus and the loss of Egypt, was determined to stop Alexander. He assembled the largest army of the Persian Empire — perhaps 50,000 to 100,000 men, by the most reasonable ancient estimates — and chose a broad plain in northern Iraq where his cavalry and his famous scythed chariots could maneuver freely. The plain of Gaugamela, near the modern town of Dohuk, was flat and well-watered, and it had been leveled by the Persians in advance to give their chariots an even field.
The Two Armies
The Persian army was a coalition of the subject peoples of the Achaemenid Empire. The core was the Persian cavalry, including the famous Immortals (a force of about 10,000 infantry), the Bactrian cavalry from Central Asia, the Indian cavalry from the Indus valley, and the Parthian and Sogdian horse archers. The Persian army also included a large number of war elephants, several hundred scythed chariots, and a huge mass of infantry from the various subject peoples.
Alexander’s army was smaller but more disciplined. The core was the Macedonian phalanx, equipped with the long pike (the sarissa) and trained in the tactics developed by Alexander’s father Philip II. The phalanx was supported by the famous Companion Cavalry, the elite heavy cavalry of the Macedonian army, led by Alexander himself. The army also included light infantry, Cretan archers, Macedonian slingers, and a small force of mounted Thessalians.
Alexander’s total force was about 47,000 men, of whom about 7,000 were cavalry. The Persian force is uncertain but was probably 50,000–100,000 men, with a much larger proportion of cavalry and a much larger number of chariots and elephants.
The Battle
The battle began on the morning of 1 October 331 BCE. Alexander deployed his army in the typical Macedonian fashion, with the phalanx in the center and the Companion Cavalry on the right. The Persians, who had studied Alexander’s tactics at Issus, expected Alexander to lead a cavalry charge against Darius himself, and they had positioned the Indian and Bactrian cavalry to flank any such attack.
Alexander, however, used a feint. He advanced his army at an oblique angle to the right, as if he intended to outflank the Persian left, and the Persians shifted their line to the right to meet him. Alexander then suddenly wheeled his Companion Cavalry to the right, and the Companion Cavalry, led by Alexander himself, charged directly into the gap that had opened up in the Persian line. The Persian center broke, and Darius, seeing his army disintegrating, fled the field on horseback.
The Persian army, despite the absence of Darius, fought on for a time, but it was eventually routed. The Persian center and left collapsed, and the right wing of the Persian army was driven from the field. Alexander’s phalanx and his supporting cavalry took heavy losses, but the Macedonian victory was decisive. The Persian army was routed, and Alexander had effectively won the war.
The Aftermath
The Battle of Gaugamela ended the Persian Empire. Babylon, the largest city of the world, surrendered without a fight, and Alexander was welcomed as a liberator. Susa, the second capital of the empire, followed. Persepolis, the ceremonial capital, was taken after a brief siege, and according to the ancient sources Alexander burned the great palace of the Achaemenid kings in revenge for the Persian burning of Athens in 480 BCE. (The story is probably not literally true, but it became one of the most powerful images in Western tradition.)
Darius fled eastward, and one of his own satraps murdered him before Alexander could reach him. Alexander gave Darius a royal funeral, hunted down and executed the assassin, and then spent the next several years campaigning in the far east of the empire — in Bactria, Sogdiana, and northern India. The rest of the story is told in the Alexander the Great cluster.
The Legacy of Gaugamela
The Battle of Gaugamela was one of the most decisive battles in the history of the world. The Persian Empire, which had been the dominant power of the eastern Mediterranean and the Near East for over two hundred years, was destroyed. The Hellenistic age, in which Greek language, art, and ideas spread from Egypt to India, began. The cities that Alexander founded on his march — Alexandria in Egypt, Ai-Khanoum in Bactria, Bucephala on the Hydaspes — became centers of Greek culture that lasted for centuries.
The battle has also been the subject of intense military study. The feint, the oblique order, the sudden wheeling of the Companion Cavalry, and the pursuit of the routed enemy are all elements of the battle that have been the subject of military analysis ever since. Napoleon, the most famous of military commanders, studied the battle in detail and used its lessons in his own campaigns.
The battle is also one of the most famous events of the ancient world, and it has been the subject of literature, art, and film for over two thousand years. The famous Alexander Mosaic, recovered from the House of the Faun in Pompeii and now in the Naples National Archaeological Museum, depicts the Battle of Issus, but it is often taken to represent the Battle of Gaugamela as well. The mosaic shows Alexander charging the Persian center on his horse Bucephalus, with Darius fleeing in his chariot.