How did the Greeks win the Battle of Marathon?

In order to understand the Battle of Marathon, it is important to first understand the historical context surrounding it. 

In 490 BC, the Persian Empire was the largest empire in the world. They had conquered many lands and peoples, including those in modern-day Turkey, Iraq, Iran, Afghanistan, and Pakistan.

It was ruled by King Darius I, who was considered to be an able administrator and clever military commander.

The Greeks, on the other hand, were not a united empire like the Persians. Instead, the Greeks were a people who were divided among individual cities.

Most peoples in the Greek world were more loyal to their city-states than to any idea of 'Greek-ness'.

These cities were, however, united by a common culture and language. Despite this, it was very common for the various Greek city-states to be at war with one another.

At the beginning of the 5th century BC, the Greek states were forced to put their differences aside if they hoped to create a united front against Persian aggression.

Darius may not have had any interest in invading Greece initially, as it was a small region on the edges of his empire.

However, Athens' involvement in the Ionian Revolt changed his mind. 

The Ionian Revolt was a rebellion by the Greek city-states of Ionia (modern-day Turkey) against Persian rule.

The Ionians had been conquered by Persia some years earlier and were now forced to pay tribute to the Persian king.

In 499 BC, they rebelled and asked for help from the city-states on mainland Greece. 

The Athenians responded to this request and sent ships and troops to aid the rebels.

This angered Darius and he vowed to punish Athens. He began making plans for a full-scale invasion of Greece.

Darius ordered the coastal cities of Asia Minor to provide 200 ships to help transport his invasion force, which numbered around 25,000, to Greece. 

This Persian army was commanded by Datis, an experience Median admiral, and Artaphernes, the nephew of Darius.

Accompanying them as a military adviser was the former tyrant of Athens, Hippias, who hoped to be appointed as Persia's ruler over Athens following the assumed victory. 

Once assembled, the Persian fleet island-hopped across the Aegean Sea, stopping at the islands of Samos, Naxos, and Delos, and secured their support for their invasion. 

When they arrived at the island of Euboea, close to mainland Greece, they attacked the cities of Carystus and Eretria.

They were both destroyed as punishment for their role in supporting the Ionian Revolt.

Then, in September 490 BC, the fleet finally arrived at Marathon in Attica (modern-day Greece). 

The vast, flat plain of Marathon was about 26 miles (about 42 kilometres) from Athens, and the Persians planned to march on the city and take it by force.

When news of the landing reached Athens, there were arguments in the Assembly about the best course of action. 

Some Athenians wanted to remain behind the safety of the city's walls and prepare for a siege, while others argued that the army should take the initiative and march out to attack the enemy.

The Athenian politician, Miltiades, who was elected as one of city's ten generals (strategoi) in 490 BC, managed to convince the people to march out of Athens to meet the threat head-on.

He did this since he feared that long-time supporters of Hippias who still lived in the city might surrender Athens to the Persians.

So, Miltiades' recommendation finally won the day and the soldiers headed towards Marathon.

However, the Athenians knew that they would be outnumbered by the invaders, so also sent a messenger to the Spartans, appealing for their military support.

The Spartans did offer to help, but they were observing a religious event, known as the Karneian Festival, at that time, which prohibited them from leaving until the next full moon.

When the Athenian troops arrived at Marathon, they positioned their forces in the foothills of Mt Pentelicus, which was a strong defensive location.

Here, they could either wait for potential Spartan reinforcements to arrive or brace themselves for the Persian attack.

From the foothills, they could survey their enemy's numbers. The Persian army had around 25,000 troops which had already been disembarked onto the plain.

They vastly outnumbered the Athenians, who had only around 10,000 of their own hoplites.

However, the Athenian force was also supported by an additional 600–1000 hoplites from the allied city of Plataea.

Regardless, it was still no match for the Persians.

In fact, the site of Marathon had been specifically chosen as a landing site for the Persians because it offered ideal terrain for their powerful horsemen.

The Persian army also employed large units of archers, who would rain arrows down on the Greeks from a distance.

The Greek army, on the other hand, was primarily composed of hoplites, who were infantrymen armed with spears and swords.

When the Persians saw the Greek forces arriving, they left their camp and lined up about 1.5 kilometres from them in preparation for battle.

However, both sides waited for several days for the other to make the first move.

In the Athenian camp, the ten strategoi could not reach a clear consensus about the best course of action.

Five of them, including Miltiades, wanted to attack as soon as they could, while the others, including Callimachus, wanted to wait for reinforcements.

To break the deadlock, Miltiades successfully encouraged Callimachus to change his mind.

Having made the decision to attack, the Greeks were suddenly alerted to the fact that the Persian cavalry was missing from camp.

The surviving historical sources are not clear where they had gone. It has been suggested that they may have returned to the ships in preparation for a surprise attack on Athens by sea, or that they had been moved north to find better grazing ground.

Regardless, Miltiades believed that it was a valuable opportunity to attack the Persians while their greatest threat was absent, and he ordered the Greeks to prepare.

Miltiades ordered his men to march quickly towards the Persian line. In response, the Persian archers fired arrows at the Greeks, but they were too light to cause significant damage to the bronze-armored hoplites.

Then, when the Greek soldiers were around 400 metres from the enemy, Miltiades orders his men to sprint straight at the opponent's lines.

This was a risky move, as running in heavy armour would quickly tire out the soldiers, leaving them exhausted when they finally began fighting with their enemy.

However, as Miltiades had hoped, the Greek charge caught the Persians by surprise. 

They were not expecting such a bold move from the Greeks and were unprepared for it.

In the centre of the battlefield, the overwhelming Persian numbers successfully broke through the Greek line, which was often a sign of an impending victory.

However, on the left and right wings of the battle, the Greeks successfully drove the Persians back.

This meant that the Persians in the centre were now surrounded on both sides by the Greeks and bloody hand-to-hand combat began.

Soon, the Persian forces panicked, turned, and fled back towards the safety of their ships.

The Athenian soldiers pursued them and killed many more of them as they tried to escape.

In all, it is estimated that around 6000 Persians died in the Battle of Marathon, while only 192 Athens soldiers were killed.

Unfortunately, the Greek general Callimachus was among the dead.

The Persians that made it back to the ships did not give up on their plan to conquer Athens and, instead, sailed around the coast of Attica towards the city.

When they arrived, they found that the Athenians soldiers had quickly marched back from Marathon and were ready to fight again. 

Unwilling to face another defeat so quickly after the disaster at Marathon, the Persian forces then finally gave up and sailed back to Persia.

It is important to note that Sparta did eventually fulfil its promise to send troops, and 2000 Spartan hoplites arrived in Athens well after the battle was over.

They were so surprised to learn of Athens' stunning victory, that the Spartans asked to be shown the battlefield themselves.

King Darius was so angry about his defeat at Marathon that he vowed to take revenge on the Greeks.

He planned to lead another expedition against them, this time with an even larger army.

In addition, the news of the Athenian victory at Marathon spread quickly throughout Greece.

The Greeks cities were ecstatic that they had defeated such a large Persian force.

The Athenians decided to commemorate their victory by erecting a burial mound (Soros) on the battlefield for the fallen soldiers and inscribed the names of each of the dead on a marble pillar.

The Battle of Marathon was the first time that the Greeks had defeated the Persians in open combat.

Therefore, it showed the Greeks that they could resist Persian rule, and it inspired them to fight for their freedom.

Also, modern races that are called 'marathons' are based upon this battle. The marathon race distance of 42 km (26.2 miles) is based upon the legendary run of a Greek soldier named Pheidippides from the plains of Marathon to Athens in 490 BC to announce the Greek victory over the Persians.

This run later inspired the marathon event at the first modern Olympic Games in 1896. 

In fact, the first modern marathon actually followed a course from the town of Marathon to Athens, which retraced Pheidippides' route.