Alexander the Great's major battles

Alexander the Great, born in 356 BC, was a warrior from a very young age, fighting his first battle, at Chaeronea, when only 18 years old. He spent virtually the whole of his short life as a campaigner, waging war firstly to defend the Kingdom of Macedonia and then to build an empire that was unrivalled at its time.

The Battle of Issus

The Battle of Issus (333 BC) probably counts as Alexander’s first major battle in his campaign against the Persians, whose forces, led by Darius III, outnumbered those of Alexander, although traditional estimates of Darius’s army comprising more than half a million men are probably gross exaggerations. Alexander had crossed the Hellespont into Asia Minor with a force of no more than 35,000 men, although he had probably doubled this number by the time of the battle, whereas Darius could certainly have commanded at least 100,000.

Alexander won the battle by making good use of his cavalry to form a mobile attack force that could pick off weaker elements of the Persian army and then retreat. The battle was decided when a direct assault on the Persian centre led to Darius fleeing the battle, leaving his wife, mother and children behind. These family members then became hostages; they were well treated by Alexander, but proved to be valuable bargaining chips in future dealings with Darius.

The Battle of Gaugamela

The next major battle between the two sides was in October 331 BC. The battle was fought at Gaugamela, although it is sometimes known as the Battle of Arbela. The modern Iraqi city of Mosul is not far away. Again, ancient sources have distorted the figures, but it is probable that Alexander had around 30,000 troops as against Darius’s 50,000. Alexander’s tactic was to encourage the Persian cavalry to attack his flanks, so that he could advance towards the centre, commanded by Darius himself. He also devised a trap to render useless the Persians’ new weapon, namely the battle chariot.

As at Issus, Darius proved to have little personal courage, and he once again fled the field. He retreated to Persepolis, the Persian capital, to rebuild the army, and was later murdered by Bessus, the ruler of Bactria, who then proclaimed himself King of Persia.

The Persian Gate

Alexander’s progress into Persia (modern day Iran) was through the Zagros Mountains, and it was at a pass known as the Persian Gate that he fell into an ambush led by the Persian general Ariobarzan. Alexander only had about half his army with him, and was taken totally by surprise by the ambush, which initially inflicted heavy losses, despite Ariobarzan only having about 700 men under his command. The action held the Macedonians at bay for about a month, but eventually Alexander was able to outflank the Persians and defeat them with a surprise attack of his own. There are stories that Alexander was shown the path through the mountains by a shepherd boy.

The Batte of the Hydaspes River

Alexander’s last major battle was at the Hydaspes River (now known as the Jhelum) in 326 BC. This was against the Indian King Porus, and occurred after Alexander had finally defeated the Persians and was advancing into India. For once, Alexander had a significant battle force under his command, probably as many as 55,000 men, but the opposing forces, although smaller, included about 200 war elephants, calculated to sow terror in the hearts of troops from far-off Europe.

The two armies were separated by the swift Hydaspes River. Alexander moved upstream to cross the river and return on the Indian bank, but gave the Indians the impression that the bulk of the army had stayed behind. Porus therefore only sent a small force to oppose them, and this was easily routed. He then realised that a greater force was needed and advanced with the bulk of his army, leaving the way clear for the rest of the Macedonian force to ford the river and attack the Indians from both sides.

Alexander appreciated that the war elephants were a powerful weapon, especially as they really did “frighten the horses”. He therefore adapted his tactics so that the cavalry were kept as far away from the elephants as possible.

Victory was assured, but at much greater cost than the Macedonians were used to. Alexander faced something of a mutiny, and this was therefore the furthest point of his conquests. He spent the rest of his campaign (only three more years before his death from disease at the age of 32) consolidating his empire in Persia and Mesopotamia.

Later generals learned much from studying Alexander’s battle tactics, particular his reliance on using fast cavalry units to outflank the enemy, the element of surprise, and his ability to change tactics at short notice when the occasion so demanded. Despite his youthful years, Alexander was certainly one of the cleverest generals ever to grace a battlefield.

© John Welford