You are an officer in the Athenian army. The Persians have just landed at Marathon to invade Greece. Write a letter to a friend explaining why the Athenian army did not go out to fight the Persians when they arrived at Marathon.

On the morning of September 17, 490 bc, some 10,000 Greeks stood assembled on the plain of Marathon, preparing to fight to the last man. Behind them lay everything they held dear: their city, their homes, their families. In front of the outnumbered Greeks stood the assembled forces of the Persian empire, a seemingly invincible army with revenge, pillage and plunder on its mind.

The Athenians’ feelings are best expressed by Aeschylus, who fought in the Persian wars, in his tragic play The Persians: "On, sons of the Hellenes! Fight for the freedom of your country! Fight for the freedom of your children and of your wives, for the gods of your fathers and for the sepulchers of your ancestors! All are now staked upon the strife!"

The two sides faced each another directly, waiting for the fight to start. The Athenians stalled for days, anticipating reinforcements promised by Sparta. But they knew they could not wait for long. The Persians, expecting as easy a victory as they had won against enemies so many times before, were in no hurry.

The Greeks, knowing the time for battle had come, began to move forward. Ostensibly, they advanced with focus and purpose, but beneath this firm veneer, as they looked on a vastly larger enemy - at least twice their number - many must have been fearful of what was to come. The Persian archers sat with their bows drawn, ready to loose a barrage of arrows that would send fear and confusion through the Greek ranks.

"The Athenians advanced at a run towards the enemy, not less than a mile away," recounted the historian Herodotus. "The Persians, seeing the attack developed at the double, prepared to meet it, thinking it suicidal madness for the Athenians to risk an assault with so small a force - rushing in with no support from either cavalry or archers."

Had the Persian archers been allowed to loose their bows, the battle might have ended before it had truly begun. Fighting their doubts and fears, the Athenians seized the initiative and rushed the Persians. Confronted by such a bold move and realizing their infantry would be pressed into action sooner than expected must have shaken Persian confidence.

The two Athenian commanders, Callimachus and Miltiades (the latter having fought in the Persian army himself), used their knowledge of Persian battle tactics to turn the tide further in their favor. As the clatter of spears, swords and shields echoed through the valley, the Greeks had ensured that their best hoplites (heavily armed infantry) were on the flanks and that their ranks were thinned in the center. Persian battle doctrine dictated that their best troops, true Persians, fought in the center, while conscripts, pressed into service from tribute states, fought on the flanks. The Persian elite forces surged into the center of the fray, easily gaining the ascendancy. But this time it was a fatal mistake. The Persian conscripts whom the Hellenic hoplites faced on the flanks quickly broke into flight. The Greeks then made another crucial decision: Instead of pursuing their fleeing foes, they turned inward to aid their countrymen fighting in the center of the battle.