Battle of Issus (333 BC): Alexander the Great Defeats Darius III

The Battle of Issus was fought in November 333 BC on a narrow coastal plain at the north-eastern corner of the Mediterranean, in what is now southern Turkey. Alexander the Great faced the Persian king Darius III in person for the first time and routed his much larger army. Darius fled, leaving his mother, wife and children in Macedonian hands, and the victory opened the way to Syria, Phoenicia and Egypt.

Background

Darius III had come to the throne in 336 BC, the same year as Alexander, after a period of murders at the Persian court. He was an experienced member of the royal family and had a reputation for personal courage, but he inherited an empire whose western provinces were already under attack.

After his victory at the Granicus in 334 BC, Alexander spent a year conquering western and central Asia Minor. In the summer of 333 BC he crossed the Taurus mountains through the Cilician Gates, a pass the Persians failed to defend, and reached Tarsus. There he fell seriously ill, according to tradition after bathing in the cold Cydnus river, and was delayed for weeks.

Darius III had meanwhile gathered a large royal army at Babylon and marched to Syria, where he camped at Sochi, on an open plain east of the Amanus mountains. The death of his able commander Memnon of Rhodes earlier that year had ended the Persian hope of drawing Alexander back to Greece by war in the Aegean, so Darius decided to confront him directly.

The manoeuvres before the battle

Alexander advanced along the coast past Issus to Myriandrus, near modern İskenderun, intending to cross the mountains and meet Darius on the Syrian plain. Darius, perhaps believing Alexander was reluctant to fight, crossed the Amanus range by a more northerly pass and came down to the coast behind the Macedonians.

At Issus the Persians found the sick and wounded Macedonians left behind, and Arrian and Curtius say they mutilated or killed them. Darius now sat across Alexander’s line of communications. Alexander, at first hardly believing the report, sent a ship to confirm it, then turned his army back north and marched through the night to meet the Persians.

The armies and the battlefield

Ancient figures for Darius’s army are vast: Arrian and Plutarch give 600,000 men, Diodorus 400,000 infantry and 100,000 cavalry. These numbers are not credible, and historians generally estimate the Persian army at between 50,000 and 100,000 men. It included a strong force of cavalry and a large body of Greek mercenaries, perhaps 10,000 to 30,000, the best heavy infantry in Persian service.

Alexander probably had around 35,000 to 40,000 men, including about 5,000 cavalry. His core strength lay in the Macedonian phalanx, the elite hypaspist infantry and the Companion cavalry.

The battle was fought on the coastal plain between the sea and the foothills, along a small river the ancient writers call the Pinarus. Its identification is debated; the Payas river and the Deli Çay are the most commonly suggested candidates. The plain was only a few kilometres wide, which meant that Darius could not use his numerical superiority to outflank the Macedonians.

Darius placed the Greek mercenaries in his centre behind the river, with Persian infantry on either side and massed cavalry on his right, near the sea. He took his own place in the centre in his war chariot, as Persian custom required, and fortified weak points of the riverbank with palisades.

What happened

On the morning of the battle Alexander’s army marched back through the narrow coastal pass in column, then deployed into line as the plain widened. Darius, for his part, sent a screen of cavalry and light troops across the river to cover the forming of his own line, then recalled them to the wings.

Alexander placed the phalanx in the centre, the Thessalian and allied cavalry on the left under Parmenion along the shore, and himself with the Companions on the right. When he saw the Persian line, he shifted some cavalry units to strengthen the left and extended his right to counter Persian troops posted in the hills.

Alexander led the Companions across the Pinarus against the Persian left and broke it quickly. In the centre the phalanx struggled to cross the river and lost formation, and the Greek mercenaries attacked into the gaps; Arrian says about 120 Macedonian officers and men of note were killed in this fighting. On the coast, the Persian cavalry under Nabarzanes crossed the river and pressed the Thessalians hard.

Alexander then turned his cavalry inwards against the Persian centre and towards Darius. Seeing the danger, Darius fled in his chariot, later switching to a horse and leaving behind his bow, shield and royal mantle. The flight of the king caused his army to break. The Persian cavalry on the right withdrew in turn, and the retreat through the narrow passes became a slaughter. Alexander pursued until nightfall, then returned to the Persian camp.

Losses

Arrian claims that 100,000 Persians died, including 10,000 cavalry, and Diodorus gives similar figures. These numbers are certainly exaggerated, but Persian losses were clearly very heavy, especially in the pursuit. Several senior commanders were killed.

Ancient figures for Macedonian losses are low: Diodorus gives 300 infantry and about 150 cavalry killed, and Curtius reports only a few hundred dead and wounded. Alexander himself received a sword wound in the thigh. Chares of Mytilene, a court official, later claimed that Darius inflicted it personally, but Plutarch notes that Alexander’s own letter mentioned only the wound, not who gave it.

The table below sets the main ancient claims beside modern estimates. All figures are uncertain.

The royal family in captivity

In the Persian camp Alexander’s men captured Darius’s mother Sisygambis, his wife Stateira, two daughters and a young son. According to the ancient accounts, the women mourned Darius as dead until Alexander assured them he was alive. He allowed them to keep their royal titles and attendants.

A well-known story told by Arrian, Curtius and Diodorus says that Sisygambis mistakenly bowed to Alexander’s friend Hephaestion, who was taller, and that Alexander forgave her, saying that Hephaestion too was Alexander. Arrian presents the tale with caution. Sisygambis later became attached to Alexander and is said to have starved herself to death after his death in 323 BC.

Parmenion was sent to Damascus, where the Persian baggage train and treasury had been left. He captured large sums of money, many Persian nobles and their families, and Barsine, widow of Memnon, who became Alexander’s companion.

Key people

• Alexander the Great (356-323 BC): king of Macedon, aged 23.
• Darius III (ruled 336-330 BC): king of Persia.
• Parmenion (c. 400-330 BC): commander of the Macedonian left.
• Nabarzanes: Persian cavalry commander on the right wing, later involved in Darius’s murder.
• Sisygambis (died 323 BC): mother of Darius, captured after the battle.

Consequences and legacy

Darius escaped across the Euphrates with a few thousand men and sent Alexander a letter asking for the release of his family and for peace. Alexander replied, in a letter preserved in a version by Arrian, by justifying the war as revenge for past Persian aggression and demanding to be addressed in future as king of Asia and lord of all Darius’s possessions. Later Persian offers included territory and a marriage alliance; all were refused.

Instead of pursuing Darius into Mesopotamia, Alexander turned south to take the Phoenician ports that supported the Persian fleet. Byblos and Sidon submitted, but Tyre refused, leading to the long siege of Tyre in 332 BC. Egypt followed in late 332 BC. Darius used the time to raise a new army, which Alexander defeated at Gaugamela in 331 BC.

Issus also changed the balance in the Aegean. Persian commanders there had hoped to stir up revolt in Greece, and the Spartan king Agis III had sought Persian money for that purpose. News of Darius’s defeat undermined these plans, though Agis did eventually rise against Macedon in 331 BC and was defeated and killed by Antipater at Megalopolis, probably in 330 BC.

Alexander founded a city near the battlefield, Alexandria by Issus, the origin of modern İskenderun. The battle became a favourite subject of art. The most famous image is the Alexander Mosaic from the House of the Faun at Pompeii, made around 100 BC from about 1.5 million tesserae and now in the National Archaeological Museum in Naples. It is thought to copy a Greek painting of the late 4th century BC and may show Issus or Gaugamela.

In 1529 the German painter Albrecht Altdorfer painted The Battle of Alexander at Issus for the Duke of Bavaria, a vast panoramic scene now in the Alte Pinakothek in Munich and one of the best-known battle paintings of the Renaissance.

Timeline

• 334 BC, May: Alexander defeats the Persian satraps at the Granicus.
• 333 BC, summer: Alexander passes the Cilician Gates and falls ill at Tarsus.
• 333 BC, autumn: Darius marches from Babylon to Sochi in Syria.
• 333 BC, autumn: Darius crosses the Amanus and occupies Issus behind Alexander.
• 333 BC, November: Alexander defeats Darius at the Pinarus river.
• 333 BC, late autumn: Parmenion captures the Persian baggage train at Damascus.
• 332 BC, January: Alexander begins the siege of Tyre.

Why it matters

Issus was the first defeat of a Persian Great King by Alexander in person, and it shattered the prestige of Darius III. By capturing the royal family and treasure, and by turning to the coast, Alexander set the strategy that would bring him Egypt, Mesopotamia and finally the throne of Persia.