In the imperial box Helena sat back in her throne chair. The crowd, its blood lust now satisfied, was being diverted to other things as they waited for the great game of the day: the contest between Spicerius, the most famous net man in Italy, and Murranus, the Secutor, the darling of the Roman mob. Both gladiators were skilled, with a string of victories to their names. Both had received the rudis, the wooden sword of freedom, and both hoped, by the time the period of these games had finished, to receive the Corona, the crown, as Victor Ludorum, champion of the games.

In the amphitheatre the sand was being raked, turned over and dusted with sparkling grit. Attendants armed with buckets of water washed the blood stains from the marble-walled podium. In the various tiers above, the crowd moved like murmuring surf. Some hurried away to buy a drink or something to eat. Others, eager not to lose their place, shouted and bawled at the traders selling cheap wine and bitter ale, spiced sausages, honey cakes, smoked fish, sesame biscuits and even sugared figs coated in vine leaves. Musicians with trumpets tried to create music but no one really listened.

Helena sipped at a goblet of chilled white wine and leaned over in her chair, eavesdropping on her son, who’d drunk so much he was now virtually shouting, sharing his business with all in the imperial box.

‘See how these Christians love each other, eh, Rufinus?’ Constantine joked. ‘They are at each other’s throats over whether their Christ is equal to God the Father.’

Helena, however, did not regard this as funny. She needed the Christians and strove to understand their triune god. She had tried to grasp the basics. Apparently their God was three in one, Father, Son and Holy Spirit. The Son had become man, Jesus of Nazareth, yet he still remained equal to the Father, of the same substance as Him. However, a group of Christians led by a scholar called Arius believed Jesus was not equal, not of the same substance as the Father. Militiades, Bishop of Rome, had decreed this was heresy, and appealed to Helena for her son to intervene.

Helena mopped her face with a perfumed cloth. She’d had her way. Despite his mockery, Constantine owed a debt to the new religion. He had decided to celebrate his birthday by spending a week at the Villa Pulchra to the south of Rome, and had invited representatives of both Christian factions to debate the matter before him. A group of rhetoricians, public speakers, from the school in Capua had been cited by the Bishop of Rome as an example of this vexatious problem. The school was riven by the heresy, some following the teaching of Arius, others the orthodox line that Father, Son and Holy Spirit were of the same substance. Helena was astonished at how intense the theological rivalries at Capua had become. The violence over the issues was such that scholars came to their debating hall armed with swords and shields; they even had body-guards to protect them. Outside, a mob would gather, some shouting that Son was equal to Father, others that he was not. Houses had been attacked, mud and filth brought into the debating hall so opponents could be pelted. There had even been attacks at night and savage knife fights in the taverns and eating houses.

Constantine, totally mystified, had ordered three rhetoricians from either side to attend him at the Villa Pulchra. Helena closed her eyes and sighed. Constantine loved practical jokes, and liked nothing better than watching people engage in heated debate. That was fine as long as he kept his mouth shut and didn’t start roaring with laughter. Helena had done her very best to sweeten the occasion by offering lavish hospitality and the opportunity for these visiting scholars to inspect and venerate a great Christian relic, the Holy Sword, a Roman gladius miraculously preserved over the centuries, the very sword used in the execution of the Christian apostle Paul by the Emperor Nero. Now that was one thing which fascinated Helena! She had a passion for such finds and was busy collecting Christian relics. She was still searching for the Crown of Thorns thrust on to the head of the tortured Christ during his passion, the spear which had pierced his side, and the nails which had fastened the Christian Saviour to his Cross. The Holy Sword had been Helena’s greatest find so far. It would be displayed at the villa; it might even remind the Christian scholars of the need for unity.

‘Now! Now! Now!’ the crowd howled. It had slaked its thirst, satisfied its hunger and wanted the fight between Murranus and Spicerius to begin.

Helena put her cup down and turned. Behind her sat officials, notables, priests and Vestal Virgins. The latter were distinguishable by their Greek gowns with heavy over-folds, their hair hidden by white and red woollen ribbons wrapped closely round their heads and tied at the back with the ends hanging over their shoulders. But Helena wasn’t interested in them. She peered across at the far corner of the box, where a young woman sat on a stool placed advantageously on a raised tier so as to obtain a good view of the arena below. Helena winked at Claudia, her little mouse, her scurrier, her most proficient of spies. She wagered that hardly anyone in the box would have noticed Claudia, with her boyish figure and close-cropped black hair. Her skin was ivory pale, her features regular; if she possessed any beauty it was those large, lustrous eyes with their calm, unblinking gaze. She wore no paint or jewellery; just a round-necked tunic which fell beneath her knees, and on her feet stout boot sandals like those of a soldier.

Helena mouthed the words ‘little mouse’, which was acknowledged by a quick twisted smile and a bob of the head. Helena returned to her reflections. Claudia would be helpful in the problems the Emperor faced; that shrewd little mouse, that most perfect of agents, with her nose for mischief! She was a child of the slums, a former actress; she could act the lady if she wanted to but she rarely did. She did not like to be noticed, and that made her both valuable and dangerous. People chattered as if she wasn’t there, and she had a sharp eye for observing little incongruities and idiosyncrasies. Was Claudia a Christian? Helena wondered. There was certainly some link between her and the priest Sylvester, as there was with Rufinus. Perhaps the banker had promised to help Claudia find the man with the purple chalice tattooed on his wrist who had raped her two years ago after murdering her simple-minded brother Felix. Strange, Helena reflected, that Claudia had accepted her invitation to the games; the girl had declared she did not like such occasions, but wasn’t she sweet on one of the gladiators?

‘Augusta, may I join you?’ Fulvia Julia, Rufinus’s wife, was standing next to her; beside her hovered a household slave carrying a stool.

‘Of course.’ Helena’s smile was as false as Fulvia Julia’s.

‘Very good.’ Fulvia Julia sat down. ‘Augusta,’ she cooed, tapping the arm of Helena’s chair, ‘you’re so brave, refusing to wear jewellery or paint. It’s so. .’ the bitch shrilled with laughter, ‘so basic!’

‘Haven’t you read Ovid’s Remedies of Love?’ Helena smiled. ‘He says all is concealed by gems, gold and paint.’ She leaned closer. ‘A false woman is the least part of herself.’

‘Oh! Augusta, you’re so knowledgeable. Now,’ Fulvia Julia clapped her hands and pointed at the arena, ‘who do you think is going to be killed?’

Murranus the Gladiator, standing in the darkness of the tunnel entrance beneath the amphitheatre, was asking himself the same question. He’d prayed before a statue of Mars, and sprinkled some incense over the flame, mixing in a tuft of red hair from his close-cropped head. He had bathed his eyes against the dust and dabbed on a little black kohl, which emphasised their blueness. He was ready for the contest. He and his opponent were free men, so they could carry their own weapons; they would not have to wait until they entered the arena. They were here by choice. Murranus shook his head. He was here because he had to be; this was the only thing he could do — fight.