Xerxes looked down on the bedraggled child. His guards had buffeted the boy cruelly in their search for weapons. With a sea battle going on before their very eyes, the suspicion was that someone amongst the Greeks might have sent poison, or a sliver of concealed blade. The package had been broken apart, all wax stripped away and the cedar box opened and discarded. Even the piece of layered paper, formed from dried rushes in the Egyptian style, would never touch the king’s hand.

The boy trembled with a foot upon his back, face down and alone on the sandy shore. The king’s herald stood to one side, waiting for Xerxes to nod. He had been summoned for his knowledge of foreign tongues and his eyes were bright with interest as he waited to speak the words of an Athenian.

Xerxes seated himself on a throne of wood and canvas. His pavilion fluttered overhead, the entire front open, so that he could watch the triremes row past. His men fought better in his presence, Mardonius had assured him. They felt his gaze.

‘Read it to me,’ Xerxes said.

The herald took a moment to prostrate himself alongside the boy, who looked at him in confusion. When the man rose, the urchin began to rise as well. The soldier with a foot on his back had to press down to keep him still.

‘“Great King of Persia, Majesty …”’ the herald began. He spoke slowly, choosing the best words. Xerxes looked up, his interest sharpening. ‘“I, Themistocles, write as friend …” no, “ally” is the better word. “It has been my … honour to command the fleet for Athens and Greece. I would not see my people destroyed, not if I can save them.”’

Xerxes sat forward at that, then left his seat to pace while he listened. The herald raised his voice while the boy squirmed, unaware of the import of the words being read aloud in court Persian.

‘“Great Majesty, my authority is limited. Were I to call for surrender, I would simply be replaced and the battle would go on. Many more Persians would then die alongside my people. Instead, I … plead with you, I ask, as … supplicant. Your family have always shown mercy to those who ask for it. It is that time now. I see smoke rising in the city and I weep.”’