The battle of marathon was between Persia and Greece.Persia had about 15,000 people but Greece only had about 11,000. Greece won the war because they had better weapons and clever leaders. Since Greece won a messenger ran from Marathon to Athens which was a distance of just over 26 miles.
The battle of Thermopylae is a battle between Persia and Greece. During that battle to slow the Persian army the Spartans sent about 1,400 soldiers to Thermopylae. The Persians has to attack Greek cities.