‘What are they doing? Just … standing there?’

‘They are braiding one another’s hair, Majesty.’

The words brought a moment of silence as the Persians listened and decided not to look up for the king’s reaction. After a pause, Xerxes spoke again.

‘You told them we would blot out the sun with our arrows?’ he said softly.

The messenger trembled, he saw, as if he had caught an ague in the morning cold.

‘Majesty, their king replied that it was good news, as they preferred to fight in the shade.’

Xerxes nodded.

‘I am my father’s son,’ he said, raising his voice. ‘I make war to have the world shake to my steps. Not out of spite or anger, but only because God himself has decreed my right to rule. In my father’s memory, I have sought to show mercy. No more, now. No more.’

He turned to Mardonius, smiling in a brittle fashion that made him seem made of wax.

‘General. Darken the sun as I promised. Then, if any of them still live, send my hazarabam thousands, then another and another. Fill the pass with our soldiers and cut them down. They are just men. Allow no surrender, no grand gestures. The Spartans have refused my mercy. Grind them down, these who dare to stand against me, until there is nothing left.’

Mardonius grinned as he bowed. He had marched for months to reach this place. At last, he had an enemy and a purpose.

‘Thank you, Majesty. It will be done.’

Within moments, regiments of archers were jogging forward, their steps a clatter on the broken grey stones of the coast. Xerxes only wished he could see the faces of the Spartan warriors when they understood he had not been making an idle threat. He had thousands of archers and each one carried thirty arrows in a hard quiver. Between them, they could cover the sun.

Xerxes glanced up at the cliffs. He would have liked to look down as the Greeks were slaughtered, but there was no path visible. The dark crags rose like shadowed blades, impossible to climb, all while the sea crashed against that part of the coast. There was but one way through. He just had to sweep the defenders away.

Out on the sea, he could see the fleets manoeuvring. In the grey dawn, they readied themselves once more for the day’s labour, for the plunge and spite and savagery of war. Xerxes had brought them to that cold coast, but it was his father’s oath and promise they would enact. The royal house of Persia had remembered the Greeks well enough. Xerxes felt his eyes sting with pride.

The ships of Corinth fared badly against the first ranks of Persian galleys, losing a third of their number before Themistocles furiously ordered them back. He let the gasping crews rest then, sending in fresh galleys of Athens, though his heart pounded at a greater stake than anyone else endured. The allied cities had sent smaller numbers in their fleets, but with almost two hundred triremes fully crewed, the Athenian ships were literally the Assembly at sea – the free men of Athens. Behind them, they had left women and children, the old, the slaves, the foreign metics. Every man who could hold a sword and shield was either in that fleet or marching with Aristides away from Athens. There was no place of refuge, no safe harbour. They either won or they gave up all they were, all they would ever be.