A flash drew Cato’s eyes to the crest of the ridge and in the warm orange glow of the sun, low on the horizon, Roman cavalry burst upon the fleeing enemy, cutting them down as they raced towards the river. The ford could take no more than fifteen men across its width, and in a short time there was a huge tangle of men, horses and chariots desperately trying to cross the river and get away from the merciless pursuit of the Roman cavalry. Some of the Britons threw down their weapons and swam for it; scores of them splashing across the wide expanse of the Tamesis. Some, too weak or too weighed down by their clothes and equipment, began to struggle, thrashed the water briefly and then drowned.

The first of the Roman legionaries crested the ridge and marched down the slope in well ordered lines. As the men of the Third Cohort watched by the glow of the setting sun a great groan of despair swept through the packed mass of enemy warriors. Some still had enough wits about them to realise that even though they were dead men they could still take some Romans with them, and maybe win some time for the men still crossing the river. But they were too few to make a difference and were cut down as the glittering red ranks closed in around the ford.

The sun had disappeared over the horizon and the light began to fail so that it was impossible to tell the sides apart on the far bank. Only the din of thousands of men screaming in agony and shrieking for mercy told of the massacre taking place, and Cato felt relieved of the burden of seeing the terrible slaughter.

Down the slope, on the near side of the ford, the numbers of the enemy slipping past began to diminish, and they scattered in every direction, trusting to the coming night to conceal their escape. There were Roman voices from the direction of the ford, and out of the gloom behind the men of the Third Cohort came the sound of hoofs pounding along the track.

‘Cohort stand to!’ Maximius yelled, and the legionaries, still in box formation, hurriedly snatched up their shields and closed ranks as the centurions ran back to their units. A column of horsemen emerged from the dusk and drew up a short distance away, horses champing at their bits and pawing the ground as their riders sat silently.

‘Who goes there?’ Maximius bellowed.’Give the password!’

‘Pollux!’

‘Approach friend.’

An order was given and a large body of mounted men trotted past the cohort, heading down towards the ford to hunt down any enemy stragglers. Out of the shadows a small party of horsemen made for the Third Cohort.

‘It’s the bloody legate himself!’ someone close to Cato muttered.

‘Silence there!’ Cato shouted.