What is well established
The Battle of Marathon took place in 490 BCE, on a coastal plain in Attica about 40 kilometres north-east of Athens. A Persian expeditionary force landed there. An Athenian army, helped by a small contingent from Plataea, attacked it and won. The Persians then sailed away. Those core facts are widely accepted. Almost everything else, from the size of the armies to the date to the exact tactics, depends on Herodotus, the main source, and on later writers, so it carries some uncertainty.
One popular claim is false or at least unsupported: the idea that a runner carried news of victory to Athens and collapsed, giving us the modern race. That story is a later development, discussed below.
Why the Persians came
The expedition followed the Ionian Revolt, in which Athens and Eretria had briefly helped the rebel Greek cities. Darius I wished to punish those two cities, and probably also to extend Persian control across the Aegean. The wider context is set out in the overview of the Greco-Persian conflict. The force was led by two commanders, Datis and Artaphernes. It sailed across the Aegean, taking islands on the way and then capturing Eretria on Euboea.
Herodotus says Hippias, the exiled former tyrant of Athens, accompanied the Persians and suggested Marathon as a landing place. Whether the Persians hoped for support inside Athens is debated.
The armies
Later writers give the Athenian army as around 9,000 men, with about 1,000 from Plataea; Herodotus himself gives no total. These figures are plausible but not certain. He does not give a Persian figure for Marathon. Modern estimates vary widely, and any number should be treated as a rough guess. The Persians likely had a significant advantage in missile troops and some cavalry, though the role of the cavalry on the day is uncertain.
The Greeks fought as hoplites, heavily armed spearmen in a close formation. The Persian infantry used lighter equipment, with bows and shorter spears. The strengths and limits of the hoplite phalanx matter for understanding the battle: it was powerful in a close fight but exposed if it lost its order.
The Athenian command was shared among ten generals, with the polemarch Callimachus holding a leading role. Miltiades is credited by the tradition with persuading the group to fight rather than wait. A request for help was sent to Sparta, but the Spartans arrived only after the battle, because of a religious festival, according to Herodotus.
The battle
The armies faced each other across the plain for several days. According to Herodotus, the Athenians then attacked, advancing at a run for the last stretch to cross the bowshot zone quickly. Miltiades is said to have strengthened the wings of the Greek line at the expense of its centre.
The reported result:
- The Persian centre, made up of seasoned troops, pushed back the weakened Greek centre.
- The Greek wings, stronger and victorious on their own flanks, turned inward and closed on the Persian centre.
- The Persians broke and fled toward their ships, and the fighting on the beach continued as some ships were attacked.
Herodotus gives Persian losses as about 6,400 and Athenian losses as 192. The Athenian figure is the more trusted, since the dead were honoured, and a burial mound (the Soros) still stands on the plain. The Persian figure is less certain.
The withdrawal
The Persian fleet then sailed around Cape Sounion toward Athens, perhaps hoping to find the city undefended. The Athenian army marched back quickly and arrived first. Seeing it in position, the Persians left. Herodotus also tells a story about a signal, a flash of a shield, which is often repeated but whose meaning is debated.
The expedition was not a disaster for the empire, but it failed in its aim, and Darius began planning a larger invasion that his son Xerxes would carry out ten years later.
The marathon-run legend
The tradition of a runner who ran from Marathon to Athens appears much later than the battle. Herodotus mentions a long-distance runner named Pheidippides (Philippides in some manuscripts), but as a messenger who ran to Sparta, covering roughly 240 kilometres, to ask for help before the battle. Later writers, such as Plutarch and Lucian, told different versions of a runner bringing the news from the battlefield, and the names differ between accounts. The modern marathon race was created at the first modern Olympic Games in 1896, taking this later story as inspiration, and the distance was standardised later still. It is not an ancient event, and it is not part of the earliest sources for the battle. The ancient Olympic Games had no such race.
Why Marathon mattered
For the Athenians, Marathon became a point of pride. Those who fought there were remembered as a special group, and the victory was later celebrated in civic memory. It encouraged confidence in the city’s new Athenian democracy, though that democracy was less than two decades old. The Persian court, by contrast, seems to have treated Marathon as a limited setback. Its larger significance lies in what came next, when Xerxes returned in 480 BCE and the fight over Greece was decided by the fleet at Salamis and by the army at Plataea.