In reply, helmets were shoved down over topknots and ropes of hair. His men looked out from golden bronze, expressionless and cold as the mountains. The ranks behind them surged on immediately, the noise echoing. They clashed shields and spears, ready to attack at the order of Pausanias. He lengthened his gait, drawing in the cool breeze, passing through the shadow of limestone cliffs. Tisamenus kept pace easily. He bore no shield, only a long spear and a grey-blue cloak that flew out behind him. Ten thousand Spartiates and perioikoi moved smoothly to a faster pace, as they did every day in training. They ran without hard breathing, just stretching out, loosening. They would endure, as long as he asked. Pausanias felt his worry fall away. He gave a great shout, that came back from the hills. They came through the high pass, with the glare of the sun beyond.

Far at the rear, Aristides could see only a sudden surge of movement. He too had noted the Persian scouts set to watch them. Yet there had been no call to arms, no horns blown. It seemed the Spartans were just reacting to being hemmed in, opening a gap between themselves and those behind. The Athenian watched the space appear as the Spartans poured over the pass. The way was wide enough there, the land worn away by merchants and shepherds. The plains lay beyond and, perhaps, an ending. Aristides felt the eyes of his officers on him. He sighed and said a prayer to the deities of that high place. Thales of Miletus had written once that the world was full of gods. On such a day, high above the plains, it felt true.

‘Match their speed, in formation,’ Aristides ordered.

His knees protested, but at least it was in silence. His eight thousand grinned as they doubled the pace, spears high so as not to entangle the legs of those around. The air was still cold. Some of them shivered, but they were eager enough. None of them had ever dreamed of marching with Sparta against an enemy. For all the horror and blood that might lie ahead, they were in fine spirits that day.