It was fought between the citizens of Athens , aided by Plataea , and a Persian force commanded by Datis and Artaphernes. The battle was the culmination of the first attempt by Persia under King Darius I to subjugate Greece.
The Greek army inflicted a crushing defeat on the more numerous Persians, marking a turning point in the Greco-Persian Wars. The first Persian invasion was a response to Athenian involvement in the Ionian Revolt , when Athens and Eretria sent a force to support the cities of Ionia in their attempt to overthrow Persian rule. The Athenians and Eretrians had succeeded in capturing and burning Sardis , but they were then forced to retreat with heavy losses.
In response to this raid, Darius swore to burn down Athens and Eretria. According to Herodotus , Darius had his bow brought to him and then shot an arrow "upwards towards heaven", saying as he did so: "Zeus, that it may be granted me to take vengeance upon the Athenians! At the time of the battle, Sparta and Athens were the two largest city-states in Greece. In BC, he sent a naval task force under Datis and Artaphernes across the Aegean , to subjugate the Cyclades , and then to make punitive attacks on Athens and Eretria.
Reaching Euboea in mid-summer after a successful campaign in the Aegean, the Persians proceeded to besiege and capture Eretria. The Persian force then sailed for Attica , landing in the bay near the town of Marathon. The Athenians, joined by a small force from Plataea, marched to Marathon, and succeeded in blocking the two exits from the plain of Marathon.
The Athenians also sent a message to the Spartans asking for support. When the messenger arrived in Sparta, the Spartans were involved in a religious festival and gave this as a reason for not coming to help the Athenians. The Athenians and their allies chose a location for the battle, with marshes and mountainous terrain, that prevented the Persian cavalry from joining the Persian infantry.
