Read the timeline. Why was Pheidippides important?

Pheidippides was an Athenian fast runner who, according to a myth, would have sprung from the city of Marathon on the eastern part of the Attica Peninsula to Athens with the message that the Greek forces led by Miltiades had triumphed at the Battle of the Marathon in 490 BC. According to the myth, Pheidippides would have died because of the long spurge. He was sent to ask for reinforcements, before the important battle. The Spartans sent troops, but they did not come to the Marathon until the battle was over and the Persians were beaten.