Gaugamela

Military History: Alexander the Great

Chapter 7 · The Battle of Gaugamela (331 BCE)

Darius had learned from Issus (Chapter 4). This time he chose the battlefield himself: a wide, flat plain in northern Mesopotamia, where his much larger army and his cavalry would have room to surround the Macedonians. Gaugamela was the battle that decided who would rule the Persian Empire — and it is often called Alexander's masterpiece.

The Approach

Summer 331 BCE Alexander leaves Egypt (Chapter 6), marches through Syria, and crosses the Euphrates and then the Tigris, which Darius leaves undefended.
20–21 September 331 BCE A near-total eclipse of the moon. Alexander's seer Aristander declares it a sign against the Persians. Because astronomers can date the eclipse exactly, it also helps historians fix the date of the battle.
Late September 331 BCE The two armies find each other near Gaugamela. Darius has had the ground levelled so his chariots can charge.

"I Will Not Steal My Victory"

Arrian reports that Parmenion suggested a night attack, to avoid facing the huge Persian army in daylight. Alexander refused, saying he would not steal his victory. There was also a practical reason: night fighting was chaotic, and a victory won by surprise might leave Darius able to claim he hadn't really been beaten. Darius, fearing just such an attack, kept his army standing in arms all night.

The Two Armies, 1 October 331 BCE

	Macedonian army	Persian army
Strength	About 47,000: about 31,000 heavy infantry, 9,000 light infantry, 7,000 cavalry	Ancient figures of 250,000 to a million; modern estimates vary widely, often around 100,000
Special weapons	Torsion artillery and engineers, not used in the field here	About 200 scythed chariots and 15 war elephants (which seem not to have fought)
Strength of position	Discipline, flexibility, and the Companion cavalry	Numbers, open ground, and a much longer line that could overlap both Macedonian flanks

Alexander's Plan

An Oblique Line

The army advanced at an angle, with its right wing, led by Alexander, forward and its left wing, under Parmenion, held back. It also edged to the right, away from the ground Darius had levelled.

A Second Line

Behind the main line stood a second line of infantry, ready to turn and face the rear if the Persians surrounded the army.

Angled Flank Guards

On each wing, cavalry and light troops were placed at an angle, like the sides of an open box, to absorb attempts to get round the flanks.

An Old Idea, Used Boldly Leading with one strong wing and holding the other back was the idea behind Epaminondas's oblique order at Leuctra (Military History: The Greeks, Chapter 8). Alexander's version was designed not just to win on one wing, but to pull the enemy's line apart.

The Battle

1. The Chariots Fail

The scythed chariots charged. Light troops shot down many drivers and horses, and where chariots got through, the infantry opened lanes in their ranks and let them pass harmlessly, to be dealt with behind.

2. A Gap Opens

As Alexander kept moving right, Persian cavalry on Darius's left rode out to stop him getting round. This stretched the Persian line, and a gap opened between their left wing and centre.

3. The Wedge

Alexander formed the Companions and part of the phalanx into a wedge and drove straight into the gap, toward Darius himself. As at Issus, Darius fled, and the Persian centre began to collapse.

4. Trouble on the Left

Meanwhile Parmenion's wing was hard pressed by Persian cavalry under Mazaeus. A gap opened in the phalanx, and Persian horsemen rode through it to plunder the Macedonian camp, until the second line turned and drove them off.

Did Alexander Break Off the Pursuit? Arrian says Alexander stopped chasing Darius to help Parmenion, and that the left wing had already held by the time he arrived. Some historians suspect the sources, hostile to Parmenion after his later execution, exaggerated his difficulties and blamed him for Darius's escape. Either way, Alexander chased Darius as far as Arbela, about 70 miles away, but Darius escaped again.

The End of an Empire

October 331 BCE Babylon surrenders without a fight, handed over by Mazaeus, whom Alexander makes its governor. The city's treasure falls to Alexander.
Late 331 BCE Susa, another royal capital, surrenders with an enormous treasury.
330 BCE Alexander forces the Persian Gates, a mountain pass defended by the satrap Ariobarzanes, and takes Persepolis, the ceremonial capital. Its great palace is burned — as revenge for the Persian burning of Athens in 480 BCE, or, in another tradition, after a drunken feast.
July 330 BCE Fleeing east, Darius is arrested and murdered by his own satrap Bessus. Alexander finds the body and gives him a royal burial.

Why Gaugamela Was Decisive Issus had cost Darius an army. Gaugamela cost him the empire: he couldn't raise another army of that size, and the heartland of Persian power — Babylon, Susa, Persepolis — fell within months. With Darius's death, Alexander claimed to be his rightful successor as king of Asia.

Questions to Sit With

Darius chose the ground and still lost. What did Alexander do to take away the advantages of that ground?

Was refusing a night attack sound military judgement, or pride?

Should the burning of Persepolis be seen as a military act, a political message, or neither?

Quick Reference — Chapter 7

Gaugamela was fought on 1 October 331 BCE, after a lunar eclipse on 20–21 September that helps date it
About 47,000 Macedonians faced a much larger Persian army (often estimated at around 100,000) with 200 scythed chariots on prepared ground
Alexander refused Parmenion's suggestion of a night attack
He advanced obliquely to the right, with a second line and angled flank guards
The chariots were neutralised; a gap opened in the Persian line; the Companions' wedge drove at Darius, who fled
Parmenion's wing was hard pressed and the camp raided; Darius escaped via Arbela
Babylon, Susa, and Persepolis fell; Darius was murdered by Bessus in July 330 BCE

What's Next

Chapter 8: The Real Conquest of the East: Bactria, Sogdiana & the Indian Campaign.