Such a division of Roman forces in the face of an enemy that still outnumbered them looks like a very rash command decision. Of course, General Plautius may have had good reason to believe that the risk was slight, but we shall never know. With hindsight historians always comment on the string of successes Vespasian enjoyed, but one wonders what would have happened if the Britons had been able to concentrate sufficient forces against the Second Legion. If Caratacus had managed to give the Second a nasty surprise, and defeat them, then the way would have been open for him to sweep across the rear of the rest of General Plautius’ army, destroying his lines of supply. That would have spelled disaster for the legions and may well have led to another defeat on the scale of the Varian débâcle in the German forests, where three legions had been massacred.

Such a hypothesis once again reminds us of the delicate balance of all military campaigns - a facet of history that is almost always lost in the neat narratives that subsequent historians weave around events. But for the men on the ground - the likes of Macro and Cato - the reality is always confusion, doubt and a bloody struggle for survival. A world far distant from the tidy maps and plans of generals and policy makers.

Caratacus is still at large. Defiant and increasingly desperate, he is looking for one last chance to reverse the misfortunes of the Britons. In the coming months Centurions Macro and Cato, and their comrades in the four legions of the Roman army, cannot afford to make one mistake as they seek to end the deadly duel with their increasingly desperate and fanatic enemy.