Battle of Gaugamela

The Battle of Gaugamela (Γαυγάμηλα) took place in 331 BC between Alexander the Great and Darius III of Persia. Also called the Battle of Arbela, it was a decisive victory for the Macedonians and led to the fall of the Persian Empire.

Location
Darius chose a flat, open plain where he could deploy his larger forces, not wanting to be caught in a narrow battlefield as he had been at Issus two years earlier, where he was unable to deploy his huge army properly. Darius had his soldiers flatten the terrain prior to the battle, so as to give his 200 war-chariots optimal conditions. However, this did not matter. On the ground were few hills and no bodies of water that Alexander could use for protection, and in the autumn the weather was dry and mild. The most commonly accepted opinion about the location is (36.36°N, 43.25°W), east of Mosul in modern-day northern Iraq – suggested by Sir Aurel Stein in 1938 (see his Limes Report, pp. 127–1)

Background
During the two years after the Battle of Issus, Alexander occupied the Mediterranean coast and Egypt. He advanced from Syria against the heart of the Persian empire, crossing the Euphrates and Tigris rivers without any opposition. Darius was building up a massive army, drawing men from all parts of his empire, more than 250,000 soldiers (including more than 42,000 cavalry) against approximately 47,000 Macedonian soldiers (including around 8,000 cavalry). Just before the battle, Darius offered Alexander a generous peace agreement: he would cede half the Persian Empire if Alexander ceased his invasion of Persia, but Alexander declined without any consideration. One of Alexander's generals, Parmenion, said that if he were Alexander he would gladly accept the more-than-generous offer. Alexander replied, "And I would too, if I were Parmenion."

Time of attack
On the eve of battle Alexander's generals, including Parmenion, suggested that to counter the overwhelming number of Persians, a surprise night attack should be launched. Alexander dismissed this, proclaiming that he would not "steal his victory". This was either a lucky move or a stroke of genius: Darius, fearing a night attack, kept his army awake and on alert for the whole night, while Alexander's was allowed to sleep. The next morning, Alexander over-slept. When his concerned generals woke him, he stated matter-of-factly that the battle had already been won.

Modern estimates
Some ancient Greek historians suggest that the main Persian army numbered between 200,000 and 300,000, but some modern scholars suggest that it was no larger than 50,000 because of the logistical difficulty of fielding more than 50,000 soldiers in battle at the time. However, it is possible that the Persian army could have numbered over 100,000 men. One estimate is that there were 25,000 peltasts, 10,000 Immortals, 2,000 Greek hoplites, 1,000 Bactrians, and 40,000 cavalry, 200 scythed chariots, and 15 war elephants. Hans Delbrück estimates Persian cavalry at 12,000 because of management issues, Persian infantry (peltast) less than that of the Greek heavy infantry, and Greek mercenaries at 8,000.

Warry estimates a total size of 91,000; Welman 90,000; Delbrück (1978) 52,000; Engels (1920) and Green (1990) no larger than 100,000.

Ancient sources
According to Arrian, Darius's force numbered 40,000 cavalry and 1,000,000 infantry, Diodorus Siculus put it at 200,000 cavalry and 800,000 infantry, Plutarch put it at 1,000,000 troops (without a breakdown in composition), while according to Curtius Rufus it consisted of 45,000 cavalry and 200,000 infantry. Furthermore according to Arrian, Diodorus, and Curtius, Darius had 200 chariots while Arrian mentions 15 war elephants. Included in Darius's infantry were about 2,000 Greek mercenary hoplites.

While Darius had a significant advantage in numbers, most of his troops were of a lower quality than Alexander's. Alexander's pezhetairoi were armed with a six-metre spear, the sarissa. The main Persian infantry was poorly trained and equipped in comparison to Alexander's pezhetairoi and hoplites. The only respectable infantry Darius had were his 10,000 Greek hoplites and his personal bodyguard, the 10,000 Persian Immortals. The Greek mercenaries fought in a phalanx, armed with a heavy shield but with spears no longer than three metres, while the spears of the Immortals were 2 metres long. Among the other Persian troops, the most heavily armed were the Armenians who were armed the Greek way, and probably fought as a phalanx. The rest of Darius's contingents were much more lightly armed; the main weapon of the Achaemenid army historically was the bow and arrow, and javelin.

Modern estimates
Alexander commanded a force from his kingdom of Macedon, Thracian allies, and the Corinthian League that—according to Arrian, the most reliable historian of Alexander (who is believed to be relying on the work of the eye-witness Ptolemy) – numbered 7,000 cavalry and 40,000 infantry. Most historians agree that the Macedonian army consisted of 31,000 heavy infantry, including the Greek hoplites in reserve, with an additional 9,000 light infantry consisting mainly of peltasts with some archers. The size of the Macedonian mounted arm was about 7,000.

Initial dispositions
The battle began with the Persians already present at the battlefield. Darius had recruited the finest cavalry from his Eastern satrapies and from an allied Scythian tribe and deployed scythed chariots, for which he had ordered bushes and vegetation removed from the battlefield to maximize their effectiveness. He also had 15 Indian elephants supported by Indian chariots.



Darius placed himself in the centre with his best infantry as was the tradition among Persian kings. He was surrounded by, on his right, the Carian cavalry, Greek mercenaries, and the Persian horse guards. In the right-center he placed the Persian foot guards (Apple Bearers/Immortals to the Greeks), the Indian Cavalry and his Mardian archers.

On both flanks were the cavalry. Bessus commanded the left flank with the Bactrians, Dahae cavalry, Arachosian cavalry, Persian cavalry, Susian cavalry, Cadusian cavalry, and Scythians. Chariots were placed in front with a small group of Bactrians. Mazaeus commanded the right flank with the Syrian, Median, Mesopotamian, Parthian, Sacian, Tapurian, Hyrcanian, Caucasian Albanian, Sacesinian, Cappadocian, and Armenian cavalry. The Cappadocians and Armenians were stationed in front of the other cavalry units, and led the attack. The Albanian and Sacesinian cavalry were sent around to flank the Greek left.

The Macedonian were divided into two, with the right side under the direct command of Alexander, and the left of Parmenion. Alexander fought with his Companion cavalry. With it were the Paionian, and Greek light cavalry. The mercenary cavalry was divided into two groups, veterans on the flank of the right and the rest in front of the Agrians and Greek archers, which were stationed next to the phalanx. Parmenion was stationed on the left with the Thessalians, Greek mercenaries, and Thracian cavalry. There they were to pull off a holding maneuver while Alexander landed the decisive blow from the right.

On the right-centre were Cretan mercenaries. Behind them were Thessalian cavalry under Phillip, and Achaean mercenaries. To their right was another part of the allied Greek cavalry. From there came the phalanx, in a double line. Outnumbered over 5:1 in cavalry, with their line surpassed by over a mile, it seemed inevitable that the Greeks would be flanked by the Persians. The second line were given orders to deal with any flanking units should the situation arise. This second line consisted of mostly mercenaries.

Beginning of the battle
Alexander began by ordering his infantry to march in phalanx formation towards the center of the enemy line. The Macedonian advanced with the wings echeloned back at 45 degrees to lure the Persian cavalry to attack. While the phalanxes battled the Persian infantry, Darius sent a large part of his cavalry and some of his regular infantry to attack Parmenion's forces on the left.

During the battle Alexander used an unusual strategy which has been duplicated only a few times. While the infantry battled the Persian troops in the center, Alexander began to ride all the way to the edge of the right flank, accompanied by his Companion Cavalry. His plan was to draw as much of the Persian cavalry as possible to the flanks, to create a gap within the enemy line where a decisive blow could then be struck at Darius in the center. This required almost perfect timing and maneuvering, and Alexander himself to act first. Alexander would force Darius to attack (as they would soon move off the prepared ground) though Darius did not want to be the first to attack after seeing what happened at Issus against a similar formation. In the end Darius' hand was forced, and he attacked.

Mouse-trap tactic
Darius now launched his chariots, some of which were intercepted by the Agrianians (javelin throwers). It is said that the Greek army had trained for a new tactic to counter these devastating chariots if they ran into their ranks: The first lines would step aside, opening a gap. The horse would refuse to run into the spears of the front ranks, and enter the "mouse trap", to be stopped by the spears of the rear ranks. The charioteers and their horses could then be killed at leisure.

Alexander's decisive attack
As the Persians advanced farther and farther to the Greek flanks in their attack, Alexander slowly filtered in his rearguard. Alexander disengaged his Companions, and prepared for the decisive attack. He formed his units into a giant wedge, with him leading the charge. Behind them were the guards brigade along with any phalanx battalions he could withdraw from the battle. These were follow-up light troops. Alexander took most of his cavalry and moved parallel to Darius's front lines, heading off of the prepared battlefield. In response, Darius ordered his cavalry in the front lines to block Alexander's force. Unknown to Darius, Alexander hid a force of peltasts (light infantry armed with slings, javelins, and shortbows) behind his horsemen and slowly sent his force into an angle, heading toward the Persian host, until finally a gap opened between Bessus's left and Darius's center and Alexander sent in his cavalry to drive down the gap in the Persian line in a wedge formation. At the same time, the peltasts engaged the cavalry in order to keep them from riding back to engage Alexander's charging cavalry. The Persian infantry at the center were still fighting the phalanxes, hindering any attempts to counter Alexander's charge.



This large wedge then smashed into the weakened Persian center, taking out Darius's royal guard and the Greek mercenaries. Bessus on the left, cut off from Darius and fearing he would be struck with this wedge, began to pull back. Darius was in danger of being cut off, and the widely held modern view is that he now broke and ran, with the rest of his army following him. This is based on Arrian's account (Anabasis 3.14):


 * "For a short time there ensued a hand-to-hand fight; but when the Macedonian cavalry, commanded by Alexander himself, pressed on vigorously, thrusting themselves against the Persians and striking their faces with their spears, and when the Macedonian phalanx in dense array and bristling with long pikes had also made an attack upon them, all things together appeared full of terror to Darius, who had already long been in a state of fear, so that he was the first to turn and flee."

A less common view is that Darius's army was already broken when Darius ran, and is supported by an astronomical diary from Babylon written within days of the battle:


 * The twenty-fourth [day of the lunar month], in the morning, the king of the world [i.e., Darius] [erected his] standard [lacuna]. Opposite each other they fought and a heavy defeat of the troops [of the king he inflicted]. The king [i.e., Darius], his troops deserted him and to their cities [they went]. They fled to the land of the Guti.

The left flank
Alexander could have pursued Darius at this point. However, he received desperate messages from Parmenion (an event which would later be used by Callisthenes and others to discredit Parmenion) on the left. Alexander was faced with the choice of pursuing Darius and having the chance of killing him, ending the war in one stroke, but risking losing his army, or going back to the left flank to aid Parmenion and preserve his forces, letting Darius escape to the surrounding mountains. He helped Parmenion, and followed Darius later.

While holding on the left, a gap had opened up between the left and center of the Greek line. The Persian and Indian cavalry in the center with Darius broke through. Instead of taking the phalanx or Parmenion in the rear, they continued towards the camp to loot. They also tried to rescue the Queen Mother, Sisygambis, but she refused to go with them.

Meanwhile, as the center and Darius broke, Mazaeus also began to pull his forces back as Bessus had. However, unlike on the left with Bessus, the Persians soon fell into disorder as the Thessalians and other cavalry units charged forward at their fleeing enemy.

Aftermath
After the battle, Parmenion rounded up the Persian baggage train while Alexander and his bodyguard pursued Darius. As at Issus, substantial loot were gained, with 4,000 talents captured, the King's personal chariot and bow, and the war elephants. It was a disastrous defeat for the Persians and one of Alexander's finest victories.

Darius managed to escape with a small corps of his forces remaining intact. The Bactrian cavalry and Bessus caught up with him, as did some of the survivors of the Royal Guard and 2,000 Greek mercenaries.

At this point, the Persian Empire was divided into two halves–East and West. On his escape, Darius gave a speech to what remained of his army. He planned to head further east and raise another army to face Alexander, assuming that the Macedonians would head towards Babylon. At the same time, he dispatched letters to his eastern satraps asking them to remain loyal.

The satraps, however, had other intentions. Bessus murdered Darius before fleeing eastwards. When Alexander discovered Darius murdered, he was saddened to see an enemy he respected killed in such a fashion, and gave Darius a full burial ceremony at Persepolis, the former ceremonial capital of the Persian Empire, before angrily pursuing Bessus, capturing and executing him the following year. The majority of the remaining satraps gave their loyalty to Alexander and were allowed to keep their positions. The Persian Empire is traditionally considered to have ended with the death of Darius.

In film
The Battle of Gaugamela is depicted in the film Alexander (2004).

Ancient sources

 * The Anabasis of Alexander: The Battle of Gaugamela (Book 3, 7~16) By Arrian, Translated by E.J.Chinnock
 * Alexander the Great: An annotated list of primary sources from Livius.org
 * Wiki Classical Dictionary, extant sources and fragmentary and lost sources
 * Plutarch, Life of Alexander (in English)
 * Justin, Epitome of the Philippic History of Pompeius Trogus (in English)
 * Plutarch, Of the Fortune or Virtue of Alexander the Great (in English)
 * Quintus Curtius Rufus, Histories of Alexander (in Latin)

Modern sources

 * Delbrück, Hans (1920). History of the Art of War. University of Nebraska Press. Reprint edition, 1990. Translated by Walter, J. Renfroe. 4 Volumes.
 * Dodge, Theodore Ayrault (1918). Alexander: A History of the Origin and Growth of the Art of War from the Earliest Times to the Battle of Ipsus, B.C. 301. Houghton, Mifflin and Co.
 * Engels, Donald W. (1978). Alexander the Great and the Logistics of the Greek Army. Berkeley/Los Angeles/London.
 * Fox, Robin Lane (1973). Alexander the Great. London: Allen Lane.
 * Fuller, J. F. C. A Military History of the Western World. Three Volumes. New York: Da Capo Press, Inc., 1987 and 1988.
 * v. 1. From the earliest times to the Battle of Lepanto; ISBN 0-306-80304-6: pp. 87 to 114 (Alexander the Great).
 * Green, Peter. Alexander of Macedon 356–323 B.C.
 * Green, Peter (1990). Alexander to Actium; The Historical Evolution of the Hellenistic Age. Berkeley/Los Angeles.
 * Hanson, Victor Davis (2001). Carnage and Culture: Landmark Battles in the Rise of Western Power. New York: Doubleday.
 * History of the Greek Nation volume Δ, Ekdotiki Athinon, Athens 1973
 * Moerbeek, Martijn (1997). The Battle of Gaugamela, 331 BC. Universiteit Twente.
 * De Santis, Marc G. “At The Crossroads of Conquest.” Military Heritage. December 2001. Volume 3, No. 3: 46–55, 97 (Alexander the Great, his military, his strategy at the Battle of Gaugamela and his defeat of Darius making Alexander the King of Kings).
 * Van der Spek, R.J. "Darius III, Alexander the Great and Babylonian Scholarship." in: W. Henkelman, A. Kuhrt eds., A Persian Perspective. Essays in Memory of Heleen Sancisi-Weerdenburg. Achaemenid History XIII (Leiden: Nederlands Instituut voor het Nabije Oosten, 2003) 289–342.
 * Warry, John G. (1998). Warfare in the Classical World. ISBN 1-84065-004-4.
 * Welman, Nick. Battles (Major) and Army. Fontys University.