Except that barbarians, all along, had been the least of his worries. Back in Rome, where reports of the Emperor’s seven victories over the Germans were, of course, assiduously promoted, the tides of gossip surged with very different news. The execution of Gaetulicus, coming as it did so soon after the removal of two consuls, had not gone unnoticed. All three men, it was whispered, had been embroiled in the same conspiracy. It was this that explained why Caligula, determined to foil it, had left for the German front at such a furious pace. By late autumn, the news was official. Gaetulicus had indeed been executed for his ‘nefarious schemes’:25 a plot to raise the armies of the Rhine against Caligula and install a new emperor in his place.26 But who? The answer, when it came, constituted the most unexpected, most shocking revelation of all. The first token of it arrived with a delegation sent by the Emperor to the great temple of Mars the Avenger, with orders to present to the god three daggers; the second in the person of his sister, Agrippina. Just as her mother had done when bringing back the ashes of Germanicus from Syria, she arrived in Rome clasping a funerary urn. And in the urn were the remains of Lepidus.
Far from veiling the scandal, Caligula had chosen to make a full spectacle of the sordid details. Lepidus, the friend he had blessed with every conceivable favour, was reported to have grievously betrayed him. He had bedded both Agrippina and Julia Livilla; had conspired with the two sisters to seize supreme power; had spun a web of conspiracy that reached from the Senate House to the Rhine. Whether it was Gaetulicus, in a doomed attempt to secure a pardon, who had betrayed Lepidus’s role in the plot, or some other informer, no one could quite be sure; but there was no doubting the molten quality of Caligula’s hurt. Lepidus himself, ordered to bare his throat to an officer’s sword, had been swiftly dispatched; Agrippina, once she had obeyed her brother’s orders and borne her dead lover’s remains all the way back to Rome, was sent with her sister into exile. Like their mother and grandmother before them, the pair were transported to barren islands off the Italian coast, while their household possessions – jewels, furniture, slaves and all – were flogged off in Lugdunum to status-hungry Gauls.
Worse for Agrippina was to come. Shortly after the revelation of her treachery, her husband, the brutish Domitius Ahenobarbus, succumbed to dropsy, and her son, for whom she had played so dirty and hard, came into the care of his aunt, Domitia. ‘No less beautiful or wealthy than Agrippina, and of a similar age’,27 the two women were natural rivals; and Domitia, keen to win her nephew’s heart, made sure to spoil him rotten. Agrippina, who had always been as strict with the boy as she was ambitious for him, was appalled. Rotting on her prison island, though, there was little that she could do. She had already lost her freedom; now it seemed as though she might lose her son. Even so, as Caligula made sure to remind both Agrippina and Julia Livilla, they had even more to lose. ‘I have swords in addition to islands.’28
Consuls, army commanders, even members of the Emperor’s own family – all had joined in the conspiracy against him, and still their plotting had failed. Nevertheless, the shock to Caligula’s self-assurance had been seismic, and his bitterness towards his sisters unsurprising. Though he had moved swiftly and ruthlessly to crush rebellion along the Rhine and to stabilise Rome’s most militarily significant frontier, he had been left with little choice but to spend the winter reining in his plans for the conquest of Germany. The risk of further treachery was simply too great. The scale of Caligula’s suspicions was laid bare when the Senate, frantic to cover its own back, sent a delegation of grandees led by Claudius to congratulate him on his foiling of Lepidus’s conspiracy. The Emperor treated the embassy with open contempt. Most of the senators were refused entry to Gaul as potential spies; Claudius, when he arrived in Lugdunum at the head of the few granted access to the city, was pushed fully clothed into the river. Or so the story went. True or not, the rumour rammed home the point that Caligula wished to make. Those who had betrayed him could no longer expect to receive any marks of courtesy or respect. Both the Senate and his own family had been marked down as a nest of vipers. The state of war between emperor and aristocracy was now official.
All of which made it essential for Caligula to return to Italy as soon as possible. Nevertheless, this presented him with a challenge. It was clearly out of the question to depart the North without some feat to his name that he could promote in Rome as a ringing victory. So it was, with the first approach of spring, that he returned to the German front, where he inspected troops, noted with approval the improvements made by Galba to standards of discipline, and ventured another sally across the Rhine.29 In the event, though, it was not Germany which was to provide Caligula with the coup he so desperately needed, but Britain.
There, despite the fact that no legions had crossed the Channel in almost a century, Roman influence had been steadily growing. With the island carved up between an assortment of fractious and ambitious chieftains, it was only to be expected that Rome should provide them with the readiest model of power. The most effective way for a British warlord to throw his weight around was to ape the look of Caesar. The king who entertained his guests with delicacies imported from the Mediterranean, or portrayed himself on silver coins sporting a laurel wreath, was branding himself a man on the make. Such displays of self-promotion did not come cheap or easy – and it was no coincidence that the most powerful of the island’s chieftains had always made a point of staying on the right side of Rome. Cunobelin was the king of a people named the Catuvellauni, whose sway extended over much of eastern and central Britain; but that had not prevented him from setting up offerings on the Capitol, and from being assiduous in returning any Roman seafarers shipwrecked off his kingdom. Unsurprisingly, then, when one of Cunobelin’s sons was exiled after launching an abortive land-grab on Kent, the presence of Caesar on the opposite side of the Channel ensured that there was only one place for him to head.
Caligula, naturally, was delighted by this unexpected windfall. The arrival of a genuine British prince could hardly have been more timely. It was a simple matter, receiving the surrender of such a man, to represent it as the surrender of the whole of Britain. Couriers were promptly dispatched to Rome. They were ordered, on their arrival in the city, to ride as ostentatiously through the streets as possible, to proceed to the temple of Mars, and there to hand over the Emperor’s laurel-wreathed letter to the consuls. The Roman people had their tidings of victory.
And sure enough, borne on the surging of rumour, the news of it was duly repeated through the city: the dangers braved by Caesar, the captives he had taken, the conquest he had made of the Ocean. These were the kinds of detail that his fellow citizens had always loved to hear. Yet even as they were being repeated across Rome, from the Forum to taverns and washing-hung courtyards, other accounts of Caesar’s doings in the North were also circulating: cross-tides of gossip altogether less flattering to Caligula. It was claimed that he had scarpered back across the Rhine at the merest mention of barbarians; that the spoils of his supposed conquest of the Ocean were nothing but chests filled with shells; that the captives he was bringing back with him to Rome were not Germans at all, but Gauls with dyed hair. Caesonia, ever her husband’s partner in bombast and theatricality, was even claimed to be sourcing ‘auburn wigs’30 for them to wear. How was anyone in Rome, far removed from the front, to judge between two such different slipstreams of propaganda? Caligula himself, returning at high speed from the Channel for Italy, had no doubt what was at stake – nor whom to blame for the blackening of his war record. ‘Yes, I am heading back – but only because the equestrians and the people want me back,’ he informed a delegation of senators who had travelled north to meet him. ‘Do not think me a fellow citizen of yours, though. As Princeps, I no longer acknowledge the Senate.’31