Once the prisoners had been armed they boarded the vessel and loosely formed up on deck to await their officers. The two fleets were distinguished by the colour of the pennants flying from the top of each mast. The fight had been billed as a re-enactment of the battle of Salamis where the Greek warships had taken on a much larger Persian fleet and won the day. The ships chosen to represent the Persians carried light blue pennants, while those playing the part of the Greeks carried scarlet colours. One by one the other ships were similarly manned and then finally, two hours after midday, the admirals in command of the two fleets and the ships’ officers were assembled before the reviewing stand. Most of them were professional gladiators, chosen to provide the discipline and leadership needed to lead the vast number of barely trained criminals and slaves who had been forced to take part in the spectacle. Looking over them Cato could see that they were in fine condition and some carried scars from previous combat. Tigellinus called out the four sections of men that he had been holding in reserve to form a line between the fighters and the reviewing stand.

The gladiators and the Praetorians stood facing each other in silence, until Narcissus emerged on the reviewing stand and crossed to the rail to look out over the raised faces of the men who would lead thousands of men to their deaths on the lake.

Narcissus was silent for a moment before he began his address in a harsh tone. ‘In a moment the Emperor will be before you to acknowledge your salute, before the Naumachia begins. I would prefer that you were all chosen men, the very best that could do honour to the spectacle that you are privileged to take part in. But you are not. You are all that could be scraped together in the time available. Little better than the scum on those ships that you will be commanding. That said, I demand the best from you. As do they.’ He pointed towards the far shore. ‘Put on a good show. Make sure that you and your men fight well and those that survive may be rewarded.’

As the imperial secretary had been speaking, Cato noticed that some of the gladiators and the other fighters looked confused and some turned to mutter angrily to each other.

‘Silence there!’ Narcissus yelled. ‘Stand still, and show respect for your Emperor!’