In 334 BC Alexander III of Macedon, better known as Alexander ‘the Great’ set out on his grand campaign of conquest against the Persian Achaemenid Empire, aged just 22. Benefiting from the conquests, diplomacy and military reforms of his father, Philip II, Alexander had inherited a powerful professional army that utilised the phalanx formation.
He would go on to forge one of the largest empires the world had yet seen, conquering the mighty Persian Empire and marching his army as far as the Beas River in India.
Here are the four key victories Alexander gained against the Persians.
1. The Battle of the Granicus: May 334 BC
Alexander the Great at the Granicus: 334 BC.
Alexander faced his first big test not long after crossing the Hellespont into Persian territory. After visiting Troy, he and his army found themselves opposed by a slightly larger Persian force, commanded by local satraps (governors), on the far bank of the Granicus River.
The Persians were keen to engage Alexander and gain both the favour and praise of Darius, the Persian King. Alexander obliged.
The battle began when Alexander sent a portion of his cavalry across the river, but this was only a feint. As the Persians forced these men back, Alexander mounted his horse and led the Companions, his elite heavy cavalry, across the river against the centre of the Persian line.
A diagram showing the key movements of Alexander’s army at the Granicus.
A vicious cavalry fight ensued, during which Alexander very nearly lost his life. In the end, however, after many of their leaders had fallen, the Persians broke and ran, leaving the Macedonians the victors.
Alexander’s success at the Granicus marked his first victory during his Persian campaign. It was only the beginning.
2. The Battle of Issus: 5 November 333 BC
This map hammers home the narrowness of the battlefield. Darius’ compact army is visible on the left of the river, contrasted with Alexander’s neatly extended line on the right.
Alexander’s victory at the Granicus and his subsequent capture of western Asia Minor forced Darius to act. He gathered a great army and marched from Babylon to confront Alexander. The Persian King successfully outmanoeuvred his foe and forced Alexander to confront his large army (600,000 according to ancient sources, although 60-100,000 is more likely) at the Pinarus River, near Issus in southern Turkey.
After containing a small Persian force in the foothills to his right, Alexander led his elite Macedonians across the Pinarus river against the Persian force stationed on the left side of Darius’ line. Seeing Alexander’s men charging down on them the Persian bowmen released one dreadfully-inaccurate volley of arrows before they turned tail and fled.
Having broken through on the right Alexander started enveloping the rest of the Persian army, causing Darius to flee and those that remained on the field to be surrounded and slaughtered by the Macedonians.
A Roman fresco from Pompeii showing Darius fleeing from Alexander during the Battle of Issus.
After this stunning victory Alexander took Syria and subdued the city of Tyre after a lengthy siege. He then marched to Egypt in 332 BC and founded the famous city of Alexandria.
3. The Battle of Gaugamela: 1 October 331 BC
Having rejected several offers of peace from Darius, Alexander’s army campaigned through Mesopotamia, encountering another large Persian force led by the Persian King at Gaugamela on 1 October 331 BC.
Once again Alexander’s 47,000-strong army found themselves greatly outnumbered by Darius’ force. Yet this time Darius had a further advantage, having chosen a site that greatly benefited his army: a wide, open plain his soldiers had deliberately flattened.
Listen NowYet Alexander remained confident and executed an unusual strategy: with his best troops he rode to the edge of his right flank, enticing the Persian cavalry out from the centre of Darius’ line to counter him. Alexander then slowly filtered his troops back from the right and formed them into a giant wedge, smashing into the gap now created in the Persian middle.
Seeing the centre of his line carved in two Darius fled, quickly followed by many of the Persians fighting nearby. Rather than pursue, however, Alexander then needed to support the left flank of his army which allowed Darius to escape from the battlefield with a small force.
Following the battle Alexander entered Babylon, the most prestigious city in Mesopotamia, and was proclaimed King of Asia.
A diagram showing the key movements during the Battle of Gaugamela, recorded in detail by the later historian Arrian.
4. The Battle of the Persian Gate: 20 January 330 BC
Alexander may have won the Persian crown with victory at Gaugamela, but Persian resistance continued. Darius had survived the battle and had fled further east to raise a new army and Alexander now had to march through the hostile Persian heartlands.
Whilst he and his army were traversing the narrow mountain paths of the Zagros Mountains en-route to Persepolis, they encountered a strongly-fortified Persian defence at the end of a valley, called ‘The Persian Gate‘ due to the narrowness of the path at that point.
Surprised by a rain of missiles hailed down on them from the precipices above, Alexander ordered his men to retreat – the only time he did so during his military career.
A photo of the place of the Persian Gate today.
After discovering from a Persian captive in his army, who knew the region, that there was a mountain path that bypassed the Persian defence, Alexander gathered his best men and marched them through the night along this track.
By daybreak Alexander and his men had reached the end of the path behind the Persian defence and quickly began their revenge. Alexander and his men ran into the Persian camp from behind causing mayhem; meanwhile the rest of his force simultaneously attacked the Persian Gate from the front. Surrounded and overwhelmed what followed was a slaughter.
A map highlighting the key events of the Battle of the Persian Gate. The second attack track is the narrow mountain path taken by Alexander. Credit: Livius / Commons.
After crushing resistance at the Persian Gate Alexander continued deeper into Asia in pursuit of Darius. After failing to raise a comparable force to Issus or Gaugamela however, Darius was murdered by one of his Satraps in July 330 BC, and Alexander had won the Persian crown.
