Flavius Sabinus, a few years older than Vespasian, had gone ahead of his brother into the army. His progress had been slower, and at one point Sabinus had actually served as staff officer to Vespasian. It had been a situation fraught with problems of rivalry, even though the brothers had always got along well. Thanks to Vespasian’s links with Narcissus, though, Sabinus had now been elevated to an equal rank with his brother, and headed a legion of his own on this British adventure. And, as Vespasian had always known he would, Sabinus was proving effective in the field.

Certainly everything had gone well so far. The British had done nothing but sit on the bank opposite the marching camp, waiting for the Romans to hurl themselves on their rusty iron swords. Aulus Plautius’s cold calculations concerning the minds of the British leaders seemed to be working out like a Greek mathematician’s theorem, Vespasian thought - a simile he must remember for Narcissus and his letters to Claudius.

Meanwhile all eight of Plautius’s cohorts of Batavians had slipped across the river, downstream of the marching camp. The Batavians were among the most useful of auxiliary troops, Vespasian had always thought, for they were specially trained to swim across even major rivers in full battle gear.

And, after shaking themselves dry like dogs, the Batavians had fallen on the rear of the British lines. Their purpose was to disable the British chariots.

The chariots had surprised Caesar when he had come across them a century before. They were terrifyingly fast, and would bear down on you with their occupants screaming and hurling their javelins. Even the noise of their wheels was enough to panic men and horses alike. The enemy could use the chariots as a weapon in themselves, and as a way to deliver his best troops to where they would be most effective. For Caesar the chariots were a nightmare from legends of the Trojan wars, and he had had trouble countering these fluid and mobile forces with his stolid legionaries. Even his cavalry had been put under threat.

But after Caesar’s day other histories had been dusted off. It turned out that chariot-fighting had once been quite prevalent across much of northern Gaul and Germany, but it had died out in those lands centuries back. For all its mobility a chariot was vulnerable to toppling or breaking down, and its passengers spent more time riding around than in engaging the enemy. The outcome of a battle lay, as it always did, in the slow grind of infantry work. In this way as so many others, it seemed to Vespasian, the Britons on their island were out of step with developments on the continent - even with the practices of their barbarian neighbours, never mind the Romans.