How Horsemen From Thessaly Helped Win Alexander’s Greatest Victories | History Hit

How Horsemen From Thessaly Helped Win Alexander’s Greatest Victories

Alexander the Great in the battle against the Persians at the Granicus. Cornelis Troost, 1737.
Image Credit: Public Domain

Among Alexander the Great’s horsemen was a prestigious unit hailing from Thessaly, the mythological homeland of Achilles and Jason, and which extended south from Macedonia to the Aegean Sea. During the early years of his conquests, the Thessalian cavalry proved incredibly important in winning Alexander his well-known victories.

Similar to Macedonia, the region of Thessaly had a rich equine history. Its topography consisted of large fertile plains, ideal for grazing horses. The horses bred in Thessaly became famed in antiquity for both their speed and endurance and most considered them the best in Greece. It is no surprise that Bucephalus, the famed steed of Alexander, was a Thessalian horse.

Embracing their region’s suitability for rearing quality horses, the Thessalian cavalry quickly gained a reputation as the best in Greece by the time of Philip II’s reforms. Upon gaining military control of Thessaly around 344 BC, Philip incorporated units of Thessalian cavalry into his reformed Macedonian army.

Alexander also recognised the Thessalian horsemen’s quality. He brought 1,800 of them across into Asia with his great invasion force with 200 further Thessalians arriving as reinforcements soon afterwards. They were the largest allied cavalry force in his army, almost equalling the number of his Macedonian Companions.

‘Thessalian Wings’

Although similar in many respects, a soldier could tell apart Alexander’s Thessalian squadrons from the Companions by their iconic purple cloak. This robe was designed so that two corners of the robe hung down both in front and behind the wearer. When his horse galloped, a horseman wearing this cloak would be flanked by what looked like purple wings as the cloak waved up loosely behind him, thus giving the cloak the nickname ‘Thessalian Wings.’

Aside from their iconic cloak, the arms and armour of Alexander’s Thessalians were very similar to the Companions. Their kit consisted of a linen cuirass and pteruges as well as a capable Boeotian helmet and metal greaves. They carried a curved, slashing sword called a kopis, although this was their secondary weapon. Traditionally, the Thessalian cavalrymen primarily equipped themselves with two short spears. The horseman would throw one as a javelin, while he would then use the other as either a second javelin or short spear depending on the situation.

Depiction of the Companion Cavalry from Marshall Monroe Kirkman’s History of Alexander the Great (1913)

Image Credit: Public Domain

Yet by the time the Thessalian cavalry contingents had been incorporated into first Philip’s and then Alexander’s Macedonian army, it appears this weaponry had changed. By 334 BC, their main armament was a lance called a xyston, similar to that the Companions carried. It was the perfect weapon for the Thessalians’ famous formation.

The rhomboid

First developed by the tyrant Jason of Pherae just prior to the rise of Macedon, the rhomboid formation was designed for flexibility. Its diamond shape allowed the formation to easily change direction without losing its cohesiveness.

To lead the others in the manoeuvres, the best cavalrymen were placed on the sides of this formation; meanwhile the very best positioned themselves at the angle-points to lead the others when changing direction. The squadron leader, the iliarch, would be placed at the top point while a squadron closer, an ouragos, would place himself at the rear-point. Those positioned on the right and left point were called flank-guards or plagiophylakes.

When fighting in this formation, contemporaries described the Thessalians as unstoppable. Its flexibility especially was useful for when they were tasked with holding ground against an enemy cavalry attack.


Alexander structured his Thessalian cavalry very similarly to his Companions. They were formed into ile squadrons of two hundred men, each based on the various districts of Thessaly. An iliarch commanded each squadron. Like the royal squadron of the Companions, one of the Thessalian squadrons, the Pharsalian squadron, was more powerful than the rest. It consisted of 300 men and the best of the Thessalian cavalry.

At the Battle of Gaugamela for instance, the Pharsalian squadron acted as Parmenion’s personal bodyguard on the left wing – such was their quality. Keen to ensure his control over the Thessalians, Alexander appointed a Macedonian officer, called Philippus, as the overriding commander, or hipparch, of the squadrons.

Facing the Persian elite

In each of his three major battles against the Persians, the Thessalians would play a critical role. Alexander would place them on the left flank of his army – the counterpart to himself and his Companions on the right. There, the Thessalians would hold off superior Persian forces long enough for Alexander to deal the critical blow with his Macedonians.

It was the Thessalians for example that Alexander tasked with fending off the Persian army’s formidable cavalry contingents during the Battle of Issus. Although greatly outnumbered, thanks to both their quality and their use of the rhomboid formation, the Thessalians held off the Persian cavalry long enough for Alexander to rout the rest of the force. If they had not managed this, then the Persians would likely have surrounded  and annihilated Alexander’s army.

Darius flees (18th-century ivory relief)

Alexander recognised the critical role his Thessalians had played in his victory. He gave them the lion share of the spoils in Darius’ abandoned baggage train.

The end of the Thessalians

The Thessalians would not remain with Alexander for all his campaigning. By 330 BC, Alexander had captured the key Persian administrative capitals: Babylon, Susa, Persepolis and Ecbatana. In this act, the war of revenge against Persia for their invasions of Greece over 150 years before ended. Having emphasised this to his Greek allies as the main reason for his Asian campaign, he duly disbanded all his Greek contingents.

Around 130 Thessalians continued to serve in Alexander’s army as mercenaries. But within a year Alexander disbanded these men too. Regardless, the role these expert cavalrymen had played in the success of Alexander’s campaign is clear to see.

Following the departure of his Thessalians from his expedition, Alexander embraced another specialised cavalry force: specialists in horse archery recruited from the nomade Dahae of central Asia. Lightly armoured and swift-moving, in battle they acted as a highly-mobile screen in front of Alexander’s army. They would pepper their foe with volleys of arrows, keeping them preoccupied while Alexander advanced his phalanx forward. It is also likely that this unit replaced the Macedonian light cavalry as the main scouting force in Alexander’s army.

Tristan Hughes