The helots had no armour. Before the rolling dust clouds caught up and swallowed them all, Aristides saw them running with blood, still punching knives into throats and thighs, anything they could reach. They were cut down by the hundred from the first moments, killed by dark men in panelled coats. They were spitted on spears and hacked down with longer blades. Yet they did not break, those who were first in. They gave their lives in violent answer, as they had never been allowed to before.

The dust brought its own sort of fear, to those who fought in it. The scraping, kicking steps of tens of thousands coated them all, so that it settled on blinking eyes and made the sun a dim brightness. Aristides felt his vision reduce to thirty or forty men on all sides. It was like being trapped in mist, so that he marched in a ring of clear air, and all else beyond was like a terrible dream.

The clamour of metal and pain was appalling, a noise so great it seemed to batter his face and chest. Men screamed on all sides and he was instantly back in every battle he had ever known, afraid and angry, just wanting to survive, to break those who made him feel that way. He marched with the hoplite line and ahead of him, helots died like lambs. He did not think he could have stood before Persian infantry without shield or armour, with no more than a club or an eating knife. Yet they did – and they died for that wild courage. He hoped it was a kind of freedom in the end.

It was hard to judge time in the dust storm. Aristides had lost sight of the battlefield and where the main force was. He knew he should be angling towards them, to join up with Sparta and Corinth and all the rest. Yet in the chaos and confusion, lines pressed forward and turned, so that it was hard to say where he should go. He hated it, the confusion. It meant it stole away the leader he might have been and made him just a man in line, with spear and shield like any other. Aristides strode forward in tight formation, over the broken bodies of helots.

When they finally gave way, it was with a great cry of despair, so that he felt his heart break for them. The helots had run onto the swords and spears of Persians by the thousand and given their lives. Perhaps the bravest of them had all been killed, or perhaps they had been ground down in pain and blood, until there was no will left to stand. It was his worst fear, suddenly upon him. As they broke, they could sweep his hoplites aside. His Athenians would stand against a Persian line, but they could not cut down helots trying to push through, panting and bloodied.