How Did the Athenians Win the Battle of Marathon?
Few battles in the ancient world had as much impact on history as the Battle of Marathon. The battle has provided a fodder for numerous books, documentaries, and movies, which often portray the event as one of the important battles in the existential struggle between European freedom and Oriental despotism. The reality of the Battle of Marathon is much less hyperbolic and much more complex than the popular media often depicts, although it was just as important.
The Battle of Marathon was a turning point in the Greco-Persian Wars (499-449 BC) as it put a check on the mighty Achaemenid Persian military juggernaut that was threatening to inundate all of Greece and put the Greek people under their tyranny. The “Great King” Darius I (ruled 522-486 BC) of the Achaemenid Empire ruthlessly crushed the Ionian Revolt (499-493 BC) of the Greek-Anatolian city-states, which proved to be the first round of the Greco-Persian Wars and the event that placed the what was at the time the not so important city-state of Athens directly in the path of Persian aggression. The Athenians supported their Greek-Ionian cousins in the revolt, thereby making them the eternal enemies of Persians and causing Darius I to send a large amphibious invasion force to Athens in 490 BC. Despite being outnumbered, the Athenians pushed back the Persian tide on an inconsequential plain near a small town known as Marathon.
The Athenians were clearly underdogs at the Battle of Marathon, but achieved a convincing tactical and moral victory for a number of reasons that were both tangible and intangible. Among the tangible reasons for the Athenian victory were the high-quality of their commanders, especially Miltiades, who knew the capabilities and limitations of their force and what they could expect from the Persians. The Athenian commanders were familiar with the terrain and used it accordingly, as opposed to the myopic Persian commanders who relied almost solely on their numbers.
Also, the average Greek warrior, known as hoplites, were better equipped than their Persians counterparts, which proved to be vital in the latter stages of the battle. Along with the tangible and strategic factors that propelled the Athenians to victory were several intangibles that factored in their favor including: their love of freedom and rights as citizens that they did not want to lose; the fear of what the Persians would do to their city and families of they were to lose the battle; and shame over not doing more to help their Ionian Greek cousins in their time of need.
The Ionian Revolt
The event that placed Athens, and later Sparta and most of Greece, in the cross-hairs of the Persians was their involvement in the Ionian Revolt. The Greek city-states in the coastal region of the modern nation-state of Turkey, which was known in ancient times as “Ionia,” were firmly under the control of the Achaemenid Persians at the beginning of the fifth century BC as a “satrapy” or province. Ionia was listed as an Achaemenid satrapy in Persian inscriptions from Persia to Egypt and was written about by the fifth century BC Greek historian Herodotus, who noted that the province was quite lucrative as it supplied a yearly tribute of 400 talents of silver.  The mainland Greeks continued to trade with their Ionian cousins and maintained reasonable diplomatic relations with the Persians until events unfolded in Ionia in 499 BC that set them against each other permanently.
Things moved quickly in Ionia after Histiaeus – who was a Greek appointed by the Persians to rule the Ionian city of Miletus as a puppet tyrant – left the city on business and was temporarily replaced by a man named Aristagoras. The new tyrant looked across the Aegean Sea to Athens as inspiration as that city had recently overthrown its tyranny and replaced it with democracy—Aristagoras endeavored to do the same in Miletus. Soon, news spread throughout Ionia and all the Greek cities in Anatolia what Aristagoras had done and so many followed suit and expelled their tyrants. The actions were considered rebellion by Darius I who soon sent a large force to quell the growing disturbance. 
Aristagoras knew that the Ionian Greeks could not defeat the Achaemenid Empire alone, so he traveled to Greece to appeal to the two most powerful city-states, Sparta and Athens. He incorrectly gauged the austere Spartans desire for riches, who rebuffed him by stating that the time away from their city would be too long.  Aristagoras then went to Athens where he changed his pitch by appealing to the fraternal bond between Athens and Miletus as it was Athenians who founded Miletus. The plea was successful, somewhat, as the Athenians agreed to send twenty triremes, although that was far below the number Aristagoras had desired. 
The results of the Ionian Revolt proved to be disastrous for Aristagoras and the Greeks. After sacking the ancient Lydian city of Sardis, the Greeks were repulsed by the superior Persian force. Aristagoras fled the region and died in exile while the surviving Athenians sailed back to Greece, probably thinking they had heard the last of the Persians. But according to Herodotus, Darius I reportedly told his advisors: “Grant, O God, that I may punish the Athenians.”  After exacting punitive atrocities on the Ionian Greeks, Darius I assembled the largest fleet that world had ever seen to invade Greece.
The Persian Fleet Sails
The initial Persian fleet was led by a commander named Mardonius, but most of the fleet was destroyed as it tried to sail along the shoreline of the Aegean Sea.  Although thousands of men and hundreds of ships were lost at sea, the Achaemenid Empire had nearly unlimited resources available, so Darius I appointed another commander named Datis to lead another fleet to Greece. Datis’ specific orders were to “reduce Athens and Eretria to slavery” for their role in the Ionian Revolt.
Although Eretria was a much smaller city-state, the neighbor of Athens also sent triremes to support the Ionian Greeks so they also incurred the wrath of Darius I. Instead of following the Aegean coastline as Mardonius so tragically did, Datis decided to take the fleet straight across the Aegean, hopping the many Cyclades islands in the process. Once the Persian fleet arrived in Greece, Datis led it straight to Eretria to teach them a less and send a sign to the Athenians. Herodotus wrote:
“The Persians entered, and stripped the temples bare and burnt them in revenge for the burnt temples of Sardis, and, in accordance with Darius’ orders, carried off all the inhabitants as slaves." 
Once the Athenians learned of the fate of Eretria, the fear in the city must have been palpable. The Athenians knew that the Persian army was headed in their direction next and that there was little to no deal that could be made. Although Herodotus gives no numbers on the size of the Persian army, all modern scholars agree that it was larger than anything the Athenians could field. A high estimate is around 90,000, although that number includes sailors,  while a low estimate puts that number at 12,000 to 15,000 fighting men.  Whichever number is true, the Athenians were outnumbered and facing an existential threat. But the fear that the Athenians felt after the destruction Eretria may have actually worked to their advantage during the battle because they knew that if they did not win then they would die and their families would be sold into slavery.
The key to any battlefield victory is usually the result of superb planning. The Greek commanders, led by Miltiades, showed their acumen by properly mobilizing their troops, choosing the place and time to engage the Persians, and by showing creativity with their strategies in the face of overwhelming numbers. To counteract the Persian numbers, the Athenians knew that they had to muster every man they could to their cause so they started by requesting help from their allies the Spartans. Although Sparta and Athens were rivals throughout most of Hellenic history, they were allied against the Persians during the Greco-Persian Wars.
Miltiades knew that the martial minded Spartans could give them the edge against the Persians so he sent a messenger to request their assistance. The Battle of Marathon took place on September 11, which coincided with an important Spartan religious festival dedicated to Apollo Karenios, so the Athenians would have to find help elsewhere. 
Miltiades did not waste time waiting for the Spartans, though. He mobilized the entire Athenian citizenry so that all males between the ages of eighteen and forty-two would either have to fight the arriving Persians or stand guard at the city to await a potential siege. Athens had no professional, standing army in the modern sense, but its men comprised a sort of “home guard” who were able to fight on short notice. Despite not being a formal army, the Athenians were well-equipped and experienced in the arts of war. 
Once the men of Athens were mobilized, it was up to Miltiades and the other generals to decide how they would engage the Persians. Some Athenians believed that it was best to wait for the Persians and to fight them in a siege, but Miltiades knew that such a venture was doomed to failure after seeing what happened to Eretria. Miltiades argued that they needed to meet the Persians as soon as they landed their ships on ground that could favor their numerical inferiority. The Athenians chose the plain near a town named Marathon to engage the Persians because that was near where the Persians would come to shore and it was sacred to the Greek demi-god Hercules. 
The Athenians were able to muster about 10,000 hoplites and were augmented by 1,000 men from their Greek allies in Plataea. Once the Athenians picked the location, they did not directly engage the Persians, who were camped near the shore, but gradually advanced over the course of a few days, felling trees as they went. Once they arrived at would be the battlefield they were protected in their rear and flanks by rugged hills, which made the Persian cavalry useless and pinned them in a bottleneck.  With the odds somewhat more favorable, Miltiades was ready to lead his men into battle.
Miltiades next initiated two battlefield strategies that proved to be fatal for the Persians. He focused his best troops on the wings of the Greek line instead of the center, which was where the best troops traditionally fought in battles during this era. Once his troops were lined up, he ordered a nearly one mile charge by his men to engage the Persian line. Although one would think that running to a battle would wind the troops and therefore be counterproductive, in this case it had the result of rendering the Persian archery and cavalry useless.  When the two armies engaged, the Greek center gave way, but that was part of Miltiades’ ultimate strategy as Herodotus noted:
“The Athenians on one wing and the Plataeans on the other were both victorious. Having got the upper hand, they left the defeated enemy to make their escape, and them drawing the two wings together into a single unit, they turned their attention to the Persians who had broken through in the centre. Here again they were triumphant, chasing the routed enemy, and cutting them down until they came to the sea.”  At that point Datis took what was left of the fleet and tried to sail to Athens by sea. Herodotus wrote that the Persians anchored outside of the Athenian harbor before sailing back across the Aegean Sea to Ionia. 
Other Factors for Athenian Victory
Although Miltiades planning and battlefield strategies are the primary reasons why the Athenians were victorious at Marathon, there were a couple of other factors that should be considered. The fact that the Greeks had rights as citizens and were the first people to articulate the abstract idea of “freedom” that is often taken for granted today cannot be understated. The Athenians had just overthrown their tyranny in 510 BC, so most of the men fighting at Marathon knew that if they lost the battle then it would be a return to the old system. Freedom was something worth fighting for and according to Herodotus, it made the Athenians fight better.
“For while they were oppressed under tyrants, they had no better success in war than any of their neighbours, yet, once the yoke was flung off, they proved the finest fighters in the world.” 
On the other hand, all of the men in the Persian army were subjects of the Great King and had no real rights as individuals. Also, a majority of the Persian army was comprised of men from nations the Persians conquered, which means that most of them had questionable loyalties.
Finally, the average Greek soldier was better armed than even the elite warriors of the Persian army. The average Greek soldiers, known as hoplites, were well equipped with large shields, bronze helmets, bronze plate corselets, and metal greaves to protect the shins and calves. Their primary weapon was a long thrusting spear they used in the phalanx shield wall and they also carried daggers for close quarter combat.  In contrast, the “Immortals,” who were the elite soldiers of the Persian army, were equipped with quilted corselets, wicker shields, and carried spears and bows.  Essentially, the Persians were outgunned, which was a major reason why nearly 7,000 of their men were killed versus only about 200 Greeks.
The Battle of Marathon was one of the most important battles in the ancient world, if not in all of history, because it temporarily stopped the westward expansion of the Achaemenid Persian Empire and gave the allied Greek city-states a rallying cry. Although the Athenians and their Plataean allies were outnumbered at Marathon, they won a decisive tactical and moral victory for a number of reasons. The Greeks fought harder than their Persian opponents because they not only had their freedom to lose, but also the fear of what the Persians would do to their city and families for their involvement in the Ionian Revolt. Most importantly, the Athenians were led by Miltiades, who proved to be a military genius as he picked the time and place to engage the Persians in a way that nullified their numerical superiority, thereby giving the victory to Athens.
- Herodotus. The Histories. Translated by Aubrey de Sélincourt. (London: Penguin Books, 2003), Book III, 90
- Forrest, George. “Greece: The History of the Archaic Period.” In The Oxford History of Greece and the Hellenistic World. Edited by John Boardman, Jasper Griffin, and Oswyn Murray. (Oxford, Oxford University Press, 2001), p. 37
- Herodotus, Book V, 50
- Herodotus, Book V, 97
- Herodotus, Book V, 105
- Herodotus, Book VI, 44
- Herodotus, Book VI, 94
- Herodotus, Book VI, 101
- Hammond, N. G. L. “The Campaign and Battle of Marathon.” Journal of Hellenic Studies. 88 (1968) p. 33
- Dpemges, Norman A. “The Campaign and Battle of Marathon.” Historia: Zeitschrift für Alte Geschichte. 47 (1998) p. 6
- Christian, Dirk Lund, Thomas Heine Nielsen, and Adam Schwartz. “Herodotos and Hemerodromoi: Pheidippides’ Run from Athens to Sparta in 490 BC from Historical and Physiological Perspectives.” Hermes. 137 (2009) p. 161
- Sage, Michael M. Warfare in Ancient Greece: A Sourcebook. ( London: Routledge, 1996), p. 38
- Herodotus, Book VI, 108
- Hammond, pgs. 34-39
- Hammond, p. 40
- Herodotus, Book VI, 113
- Herodotus, Book VI, 115
- Herodotus, Book V, 78
- Sage, p. 26
- Sage, p. 90