‘Where’s the bloody garrison?’ grumbled one of the scouts. ‘They must have seen the convoy by now.’

Vespasian looked towards the neatly ordered lines of the fortified supply depot built on to the side of Calleva’s ramparts. Tiny dark figures were scurrying between the barrack blocks, but there were no massing ranks visible. Vespasian made a mental note to give the garrison’s commander a harsh bollocking the moment he reached the camp.

If he reached the camp, he reflected, for the skirmish was between his party and the gates of Calleva.

Unless the garrison made a sortie soon the convoy would be whittled down until the enemy could wipe it out in one final charge. Sensing that the decisive moment was near, the Durotrigans were edging closer to the wagons, screaming their war cries and striking their weapons against the edges of their shields to stoke up their battle frenzy.

Vespasian tore his cloak from his shoulders. Grasping the reins tightly in one hand, he drew his sword in the other and turned to his scouts.

‘Form line!’

The men looked at him in surprise. Their legate intended to charge the enemy, but that was tantamount to suicide.

‘Form line, damn you!’ Vespasian shouted, and this time his men responded at once, fanning out on either side of the legate, making ready their long spears. As soon as the line was ready Vespasian swept his sword down.

‘Let’s go!’

There was no parade-ground precision in the manoeuvre. The small party of horsemen just jabbed in their heels and urged their mounts to swoop down on the enemy pell-mell. Even as blood pounded in his ears Vespasian found himself questioning the sanity of this wild charge. It would have been easy enough to bear witness to the convoy’s destruction and wait until the triumphant enemy marched away from its wreckage before making for Calleva. But that would have been cowardly, and, in any case, those supplies were desperately needed. So he gritted his teeth and clenched the sword in his right hand as he made for the wagons.

Down the slope, the sound of approaching horses caused faces to turn towards them and the barrage of missiles on the convoy slackened.

‘There! Over there!’ Vespasian bellowed, pointing towards a loose line of slingers and archers. ‘Follow me!’