Aristides smiled at the memory of so many new keels, so much industry and labour. It was true he had argued against spending the Laurium silver on ships, but in the main it was to act as a check on Themistocles rather than from any true disagreement. Arguments had to be tested and teased out. It was the only way to be sure they were sound. In his heart of hearts, Aristides thought Athens would always need ships. The threat of Persia had not ended at Marathon, he was certain. Nor at Paros, where Miltiades had failed to dig them out of their stronghold with the point of a knife.

There were rumours of garrisons marching in Ionia, drawn to the far west of the Persian empire, where the coast looked out over a dozen islands ruled by Greece. Merchant traders returned with tales of brash Persian warriors appearing in the markets there, of Persian officials selling licences for all sorts of activities – and woe betide anyone who could not produce his piece of slate or pottery when visited by the tax inspectors.

To Aristides, it felt like a fist slowly closing – the influence of an empire, where once the cities of that far coast had been either Greek or independent. It worried him, more than he could say. He was due to present the accounts of the port to the council that afternoon. He toyed with the idea of making a more general speech about the rise in Persian activity.

The thought was a sour one. If Themistocles was present, as he always seemed to be, he would challenge Aristides on each point, brash and funny if he chose, or patronising, as if lecturing a child. The man’s arrogance was overwhelming, but perhaps even Themistocles would accept the empire was coming closer. In the past, King Darius had hardly acknowledged the far west, thousands of miles and hundreds of cities from his palaces and the heart. That had changed with the Ionian revolt and the burning of Sardis – then changed again with Marathon. King Darius had set his face against Greece then. He no longer drowsed and drank peach juice and forgot the distant reaches of the empire. His attention had shifted.

Aristides brushed the thought away, as if a fly had touched his face. Roads stretched across all Persia, with messengers carrying letters and jewels and tales of the interior. Trading caravans took slaves and scented oil to create perfumes as rich as any in the world. They returned with tales of monsters and men clad in gold, of striped cats as large as any lion, or huge animals with tusks tipped in silver. More than half would be fantasies and stories, told to entertain, but for a man who knew how to sift dust from good grain, there was always something to be heard at Piraeus.