‘If the order is always simply “attack”,’ Themistocles went on, ‘why have leaders and officers at all?’ Themistocles spread his hands in simple appeal. ‘Navarch, you command the fleet, but this is a matter for Athenian captains, I think. Forbid the tactic to your Spartan crews, of course, but from what I witnessed today, Athens sees the value in smaller formations – and the signals between them. I hope we can depend on your wisdom in this.’

Themistocles sat down as if the point had been settled. He looked over the group and appeared to be selecting another trierarch to speak. Eurybiades stood still and Xanthippus shook his head in irritation. The Spartan was wreathed in his own fury, growing redder by the moment.

‘If that is your final word …’ Eurybiades began.

To his surprise, the archon of the Corinthian ships called out over him.

‘Corinth stands with Athens, Eurybiades. They pinned my crews today six times, just by calling in, or scattering – some flag signals they had devised themselves. It worked, which is what matters. I would know more of those.’

Eurybiades closed his mouth as Xanthippus looked from one to the other. Not only did Corinth have forty galleys, but they were one of the cities of the Peloponnese peninsula and either an ancient ally or ancient competitor to Sparta, depending on your view. The sudden involvement of Corinth had stolen the wind from Eurybiades’ sails and he floundered.

Xanthippus rose again to stand alongside the Spartan.

‘May I speak, navarch?’ he said.

Eurybiades frowned but inclined his head and took his seat. Xanthippus chose to calm them, to give the Spartan time to reconsider.

‘My captains have named two tactics that worked best today – “periplous”, or “sailing around”, and “diekplous”, the spear-thrust.’

He cut the air with his hands as he spoke, warming to the subject. All eyes were on him as experienced men evaluated what he had to say.

‘With the first, the aim is to flank an enemy, to bring our rams to bear on his stern quarter, where he is weakest. Like this, you see? Two ships on one can achieve it, while three on one can force the kill. Where one ship alone faces another, an alert trierarch and helmsman can always turn to present the prow. It is a chaotic, exhausting business then. Numbers matter – and flag signals can be vital to bring them to the right spot. What we have today is very crude, though I saw some successes. When this blue robe of mine is torn up, we’ll have another signal tomorrow.’

There was a chuckle in the room at that and he acknowledged it. A glance aside showed him Eurybiades was still looking like thunder as he went on.

‘Diekplous – sailing through,’ Xanthippus said, with a flat palm held outstretched. ‘Our broad line becomes a point. It is dangerous, as our first ships break through their line in column, then fan out to use the rams against their side planking. Both of these work better when the captains can see individual archons and act on group orders. The final tactic is one we have called “kyklos”, or the circle. It is the last throw of the dice, if we encounter numbers so great as to overwhelm us. In that case, we pull the line back in a hollow cup formation. Each trireme forms on the next as the withdrawal …’