The Persian King, Darius I sent an invasion force the Greek mainland in the early 5th century BC following the Ionian revolt. The invasion would ultimately lead to the Battle of Marathon in 490 BC. The Athenians, afraid they were outmatched by the numerous Persians, set a runner to Sparta to ask for assistance in the fight against the Persian Empire. The Spartans would come to help but would be delayed due to religious religious festival that wouldn’t permit them to leave. The Greeks were severely outnumbered with a force of about 9,000 Athenian hoplites and 1,000 Plataen hoplites to stand against a Persian force of 24,000 infantry and 1,000 cavalry.
The Athenians had the choice of either meeting the Persians in the field or risking a siege. Knowing the Persians were masters in the art of siege warfare, the Athenians chose to meet them in open battle. A council of ten generals, each having total command for a single day, led the Greek forces. When it came to the turn of Miltiades to lead, the Athenian general decided their best course of action was to not wait for the Spartans and march out to battle the Persians. It is said in Herodotus that the Greeks charged at a run the length of 8 stades or just under a mile all the way to the Persian line, although this figure is most likely exaggerated.Many scholars believe that the Greeks marched to within range of the Persian archers and charged, then charged (Donlan and Thompson, 339-342). The heavily armed Greeks, having caught the Persians off guard, crashed into the immobile lightly armed Persian line.Thus causing considerable damage. The Persians were defeated and thrown back into the Aegean with considerable losses. The Greeks, rather unscathed, were victorious in this battle. The Persians then decided to sail around the Greek force and attack Athens while their army was away. Nevertheless, the Greek army managed to cover the ~26 miles to Athenians on land, beating the Persians to the city. Not wanting to risk more casualties, the Persians returned home defeated.
The Spartans would showed up the day after the Greek victory, asking to see the dead to study and as proof. This battle would become a great source of Athenian, as well as Greek, pride for the following decades. This was the first major engagement between the Greeks and Persians and would be the spark for the second Persian invasion in the following years.