The defeat at Marathon, Plataea, march of the 10.000, and the hold up at Thermopylae really suggest the need for some heavy infantry that can fight on par with the Greek Phalanx.

Like how much of your infantry really needs to be very mobile? The battle of Gaugamela also displays the ability of the Greek heavy infantry to deal with flanking manuevers, sort of.

  • It's the fallacy of overwhelming numbers. When all a nation's enemies are external, and small, the importance of quality can be neglected. While the Greek city states were perfecting heavy infantry tactics and armament, the Persians were too distracted with building an empire to notice. Also, don't forget Salamis - the victory that put the last nail in the Persian coffin. Read up on Davout's victories 1805-1809 for more on how well-led quality trumps quantity for more often than realized. Same again in France 1940. Jul 24, 2018 at 1:37
  • Not sure if 40s France counts - French armor was vastly superior to its German counterparts, it's lousy doctrine and lack of communication that did them in.
    – SPavel
    Jul 24, 2018 at 2:20
  • 6
    The terrain gave the Greeks at Marathon a decisive advantage, allowing a small holding force to block a much larger attacking force. Had the terrain been different, they'd have been swarmed and overcome with ease.
    – jwenting
    Jul 24, 2018 at 4:55

5 Answers 5


In hindsight, the Ancient Greek heavy infantry were vastly superior to the Persian armies. It was precisely their battles - Marathon, Thermopylae, Plataea - that demonstrated this. Before those battles, no one knew that the Greeks had a superweapon in the form of the Hoplite Phalanx in their hands. The Greeks were busy fighting each other.

As great as the Persian Empire was, its military was not its strongest point, instead it was its immense size and wealth. Due to Greece's remoteness, standard procedure was to play the various Greek city-states against each other - for example, during the Peleponnesian War, the Spartans were bankrolled by Persia.

Persia's size was intimidating to the Greeks; when Aristagoras was appealing to the Spartans to aid the Ionian Revolt, he suggested that the Persian military, as we now know, was weak. But upon hearing that it would take three months to reach Susa - one of the four Persian capitals, the Spartans firmly refused to help.

It was only after the Greco Persian wars, and knowledge gained from the Ten Thousand, that the Greeks knew it was possible to beat Persia, but first it would have to be united. This was achieved under Phillip II of Macedon, who soon planned an invasion of Persia. He was assassinated, but he was succeeded by none other than Alexander the Great.

Again, Persia turned to its strength - wealth - to compensate, in the form of funding Greek rebellions and hiring Greek mercenaries. But the misfortune of having to go up against a military machine, armed with a superweapon (Macedonian Phalanx) and not just one but two of history's greatest military minds (Phillip II and Alexander) was too much to bear.

Could Persia have produced its own heavy infantry to rival the Greeks? Arguably they did; historians like Herodotus had high praise for the Immortals. On the battlefield, although they were weaker than their Greek counterparts, they still held up well. The Persians were beaten with a combination of great logistics and tactics. Alexander could strike hard and fast, and the Persians simply couldn't keep up. The Battle of Gaugamela is typical of this: the Persian army was holding well on all fronts except for Alexander's daring attack, which drove a wedge that headed straight for Darius III, who broke and ran. This battle says more about Alexander's abilities than the quality of the two armies.

Could Persia have recreated the Greek heavy infantry? This is harder to answer. There's a theory that it's very hard to recreate superweapons like the Greek phalanx, as you need a unique combination of culture and martial tradition. The Greek Hoplite was perfected over centuries of city-state on city-state decisive warfare, over mountainous Greece. Superweapons like the English Longbow or Mongol horse archer were also inimitable for similar reasons.

So I find it hard to fault the Persians in not coming up with a good counter to Greek heavy infantry. They found out about how scary the Greeks can be as soon as anyone else, and dealt with it in a sensible way - by using their unrivalled wealth and influence to keep the Greeks divided. Having to face Alexander the Great is also a big ask; when the Romans faced Hannibal, at least they had Scipio Africanus. The Persians had Darius III.

  • 3
    Yes Darius was a big part of the Greek victory
    – user31561
    Jul 25, 2018 at 7:06
  • The terrain will point the way to people. Might not be land forces related, but was Salamis was another example of the intelligence Hellenic people had when it comes to taking advantage of the geography. After the Persians overpassed, eventually, the 300s (after Ephialtis (nightmate) betrayed them), the were simply unstoppable. The Athenians did pretty much what Russians did centuries later with Napoleon/Hitler, they just allowed the Persians to conquer Athens, and eventually have a battleship in Salamis, where the quick and flex Hellenic ships were no match for the cumbersome heavy Persian s
    – user36222
    Jan 14, 2019 at 13:45

Question: Why didn't the Persians create good infantry units?
The defeat at Marathon, Platea, march of the 10,000, and the hold up at Thermopylae would really suggest the need for some heavy infantry that can fight on a par with the Greek Phalanx. How much of your infantry really needs to be very mobile? The battle of Gaugamela also displayed the ability of the Greek heavy infantry to deal with flanking maneuvers

Why didn't the Mongols or Huns develop better heavy infantry? It was the style with which they were successful, and that model (horse based archers) remained effective long after the phalanx had disappeared from use.

I would argue that the Persians were a very successful and very respected military empire. They had battled and defeated both the Assyrians and the Babylonians. They had held off the Egyptians and they even gave Rome all they could handle in latter years. You don't conquer a large empire like Persia without having a very good army.

Yes, their heavy infantry was inferior to the Spartans at Thermopylae and Marathon but that's hardly a knock on the Persians. The Spartans went centuries without one of their armies losing. The Spartans were basically a military cult. Their entire culture and way of life was based around training for war. They even defeated the Athenians.

The battle of Gaugamela doesn't support your thesis. At Gaugamela, the Persian infantry was engaged with Alexander's phalanx. Alexander was commanding the companion cavalry and it was the use of Alexander's cavalry wedge which defeated the Persian infantry rather than the phalanx. The Persians were engaged with Alexander's phalanx and he flanked them with heavy cavalry.

In fact Alexander's phalanx with its longer spears were used to hold enemy units in front of them in order for his cavalry or archers to attrite them. Again this is not a knock on the Persians. I don't think it's a sign of incompetence to lose to Alexander the Great.

Alexander's two big advantages were:

  1. He commanded a full time professional army where other armies at the time were made up of farmers, or only part time soldiers. Alexander's father had built that Army and had trained Alexander how to use them. Their great innovation was not the Phalanx either.

  2. The Other Macedonians innovation was they had mixed units. Where other armies consisted of predominantly one kind of unit, the spartans basically used the phalanx and that's it. The Macedonians (Alexander) had heavy infantry, light infantry, heavy cavalry and light cavalry. They were flexible. Alexander was the first to use field artillery, siege weapons modified to be used against infantry. The Macedonians could put units against their enemies which maximized their enemies weaknesses. Heavy infantry was just one of the kinds of unites in Alexander's army. Alexander himself fought commanding cavalry; his companion cavalry. (heavy cavalry)

  • Although Sparta holds this image of invincibility in modern culture there's not a lot of hard evidence their soldiers were that much better in a head to head assault against their Greek contemporaries at least nothing like the level of Marathon The Mongols had not lost battles like Marathon where they overwhelmingly outnumbered their enemies so they didn't have nearly as much reason to change. There seems to be conflicting accounts of Guegamela youtube.com/watch?v=N7P8TIjBdok&t=40s youtube.com/watch?v=N7P8TIjBdok&t=40s but they all seem to agree that the
    – Hao S
    Jul 25, 2018 at 2:41
  • Persian center couldn't hold at least not in the way Alexanders left flank did.
    – Hao S
    Jul 25, 2018 at 2:43
  • @HaoSun Spartans trained in pankration, a famous martial art in Ancient Greece that consisted of boxing and grappling. Spartans were so adept in pankration that, when it was inducted in the Olympic Games, they were mostly forbidden to compete.
    – user27618
    Jul 25, 2018 at 19:48
  • @Hao Sun, Sparta had the first standing army in Europe. The first full time professional army trained from the age of seven in a grueling military school known as the Agoge. Everyone else they fought until Alexander had armies of conscripts. Armies made up of farmers and shop keepers. Their armies were feared and respected across Greece and Persia and Macedonia. The entire culture of Sparta was dedicated to war and preparation for war.
    – user27618
    Jul 25, 2018 at 19:54
  • Sparta around 650 BC, rose to become the dominant military land-power in ancient Greece. During the Peloponnesian War (431–404 BC) Sparta conquered all of Greece including Athens. The Battle of Leuctra(371 BC) was the first time that a Spartan army lost a land battle in their entire history.
    – user27618
    Jul 25, 2018 at 20:03

The Persian army at Marathon was (as at Thermopylae) at a serious disadvantage because of the terrain, which favoured the much smaller defending force tremendously.

Their failure to win in both cases is more to blame on the leadership insisting on frontal assaults on a narrow front against a force trained and equipped specifically to deter such an assault rather than on the forces sent to fight that assault. A better commander would have recognised that and kept a blocking force in place himself while sending the bulk of his forces in an encirclement in order to outflank the Greeks.

Why the Persians elected not to do this is a matter of debate among historians for a long time. Maybe they'd grown overconfident after decades or more of military successes, maybe they were cocky thinking those puny numbers of Greeks could never stand up to them, maybe they were under pressure to provide a quick victory.

Individually, I seriously doubt a Greek soldier was that much better than his equivalent in the Persian army. But the Greeks were employed much better, using the terrain to their utmost advantage where the Persians did not.

Remember also that both Greek victories came after heavy Greek losses in earlier engagements where similarly equipped and trained Greek units were wiped out by the Persians in pitched battles.

  • The Persians did win and won by outflanking the Greeks at Thermopylae and it's probable also true that man for man the Spartan hoplites were superior to the Persian soldier. The Spartans were all essentially full time professional soldiers who were selected at birth and trained from a young age. The Persian army was mostly conscripts. More importantly though when the hoplites combined into the phalanx it greatly improved their effectiveness. The phalanx was the super weapon of it's time and the Spartans were the best at using it until Alexander defeated them using mixed units.
    – user27618
    Jul 24, 2018 at 18:13
  • Thermopylae was fought by a coalition of Greeks totaling about 7000 of which the Spartans contributed 300 troops and there is little evidence the spartan hoplite was that much better than their Greek contemporaries especially considering their loss of the duel of the 300
    – Hao S
    Jul 25, 2018 at 3:50
  • @HaoSun The Spartans went centuries without loosing a battle what other country in history can say that. There were over 1000 city states in Greece and while the Spartans weren’t the largest or most populous they conquered all of them. The Spartans had the only military who had no other job but training for war. The Spartans began training for war at age 7. In individual competitions mimicking war(pankration) at the olympics Spartans were so feared they were forbidden to compete because if they competed nobody doubted they would win.
    – user27618
    Jul 28, 2018 at 16:28
  • Sparta conquered and enslaved the Helot population and established that it's military system was far superior to that of the Messenian Helots. However there is not sufficient evidence to determine the extent of it's military superiority over that of the city states of Athens and Thebes, The only example I'm aware of is Battle of Tanagra where one could argue 1 spartan was worth 1.4/1.15 athenians By this time they were largest state in land mass Also the Spartans lost Battle of the Fetters so it's not technically true that they went centuries without a defeat.
    – Hao S
    Aug 2, 2018 at 1:05
  • also that's besides the point the 300 Spartans are a minuscule portion of the Greek defense at Thermopelae and even the last stand had 700 thespians and 400 Thebans as the main force.
    – Hao S
    Aug 2, 2018 at 1:26

Another question is why did the Greeks develop good heavy infantry. Heavy infantry required a lot of discipline, mutual trust, and nerve--if part of the line broke, everyone's life was at risk (whereas in a cavalry rout individuals could still get away).

If you look at other good heavy infantry units in history, such as Flemish or Swiss pikemen, they all came from the same town/valley/canton. They knew and implicitly trusted one another, which made it easier to train them to act together. Likewise with the Greek city-state.

The Romans were the only pre-modern army, as far as I know, that developed a military machine capable of instilling sufficient esprit-de-corps in men from disparate regions. But they only did this because of their exceptional organizational abilities, which they used to scale up the infantry units of the earlier Italian city-states.

Now back to the Persians: much of their infantry was formed from auxiliaries from tributary regions. The antecedents of the core of their army were nomadic cavalry, which they scaled up into the most effective military force for thousands of miles. With such an outstanding specialty, and without any of the foundational skills to build a solid heavy infantry corps, it would be surprising if they ever did develop good indigenous heavy infantry.


One problem of Persia was that it was not one ethnicity, but a conglomerate of many different small countries. Each of these countries produced their own armies and formations, led by their own officers; there was really no central "Persian" army. So Persian military strength was on paper only; hundreds of thousands of men in "national" militias but with no central command or unified tactical doctrine. The (biblical) Book of Esther refers to "an hundred twenty and seven provinces, unto every province according to the writing thereof, and unto every people after their language," in which military commands had to be issued to the troops.

There were a "few" countries that produced better infantry formations than others. But the Persians did not identify them and insist that other countries' units learn from them. The Greek city states spoke a common language, and were geographically close, so it was easy for them to "compare notes" and develop similar infantries.

The Persians did better with cavalry troops; there were fewer of them, and they had better "natural" transportation, and hence communication, so Persian cavalry developed some cohesion.

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