In ancient times, Greece wasn't a single country like it is today. It was made up of lots of smaller states. These states were always squabbling and often went to war.
THE MESSAGE MAN
PHEW! Just 10 miles to go!
The Persian kings tried to conquer Greece a few times between 490 to 449BC, but the Greeks managed to fight them off.
The Athenian Army was outnumbered 4 to 1 but they launched a suprise offensive thrust which at the time appeared suicidal. But by day's end, 6400 Persian bodies lay dead on the field while only 192 Athenians had been killed.
After the Persians retreated they planned to attack again, Phidippides was again called upon to run to Athens (26 miles away) to carry the news of the victory and the warning about the approaching Persian ships. Despite his fatigue after his recent run to Sparta and back and having fought all morning in heavy armor, Phidippides rose to the challenge.
In the end, Athenians won with their strategic advantages and won with a small amount lost of 203 men also with the death of Phidippides, compared to Sparta's 6400 .
The war of marathon is one of the great turning points in world history. With the victory for the Athenians this gave a chance later on in history for Alexander the great to conquer the Persians instead.