Agrippa’s return to Rome was highly anticipated by Augustus. The periodic outbreaks of public disorder had still not been contained and his life continued to be the subject of plots.1 It had become crystal clear to him that Agrippa was indispensable. He needed his right-hand man not only for his willingness to go to the furthest frontiers to corral the motley confederation of disparate peoples that made up the empire, but also to help him govern the high-maintenance, petulant population of Rome. He realized how completely he had come to rely on his best friend. Privately, Agrippa must have arrived at the same conclusion. It would be years before his son Caius – Augustus’ only grandchild and direct descendant – would be eligible to enter politics. Until that time came, Agrippa would remain his most vital ally and peerless confidant, and the natural successor as princeps should Augustus’ life end before his own (fig. 8, plate 2).2
Augustus publicly recognized Agrippa’s elevated status in 18 BCE. When the five-year power of imperium proconsulare, originally granted to him in 23 BCE, expired at the start of the year, Augustus saw to it that it was renewed.3 Despite innumerable temptations over many years, Agrippa had remained unswervingly loyal to Augustus. He had demonstrated he could be trusted like no other man. In Augustus’ eyes he had earned the right to continue to have authority to govern all the imperial provinces – and the armies stationed there – for another five years. But this time, there was to be more. Augustus chose Agrippa – in Tacitus’ words – as ‘his associate (socius) in power’.4 It was a highly significant development. Dio writes ‘Agrippa was promoted to the supreme power, one might say, by him’, explaining,
he granted to Agrippa many privileges almost equal to his own, especially the tribunicia potestas for the same length of time. For that number of years, he said at the time, would be enough for them.5
Agrippa was his partner in power. On account of his personal authority (auctoritas) Augustus was still the senior man of the two, but their executive powers were now virtually identical. Important was not to be seen as ruling as a tyrant encapsulated by the terrifying Latin word dominatio. Augustus was extremely careful to avoid any suggestion that he was a king in all but name, or that Agrippa was his co-regent.6 Their titles and powers were those of the traditional magistrates of the Roman constitution. Yet it was also a consummately pragmatic solution which suited the Roman political temperament. Just as there were two consuls of the Res Publica in Rome, so there were two supreme caretakers of the greater Roman Empire, and the powers of each were also explicitly defined in law and limited in duration.7 In this way, while his legal powers were equally matched by another’s, Augustus could not be portrayed as a dictator –or worse as rex, king.
There were dissenters. Schemes were hatched – or so it was supposed. The regime began to show signs of paranoia. ‘Many immediately and many later were accused,’ writes Dio, ‘whether truly or falsely, of plotting against both the emperor and Agrippa.’8 An insight into how Agrippa felt about power and government is preserved in a proverb in which Seneca records that Agrippa ‘used to say that he was greatly indebted to’.9 The origin of the maxim is itself revealing. The historian Sallust (C. Sallustius Crispus) – who was a novus homo from a provincial family, became a politician in Rome and might have been known to Agrippa – wrote about Rome’s war of 111–105 BCE against the Numidians. Before Micipsa, king of the Numidians, died he called for his natural sons Adherbal and Hiempsal, and his nephew by adoption, Iugurtha, to come to him. He explained it was his great wish that all three men would share his kingdom among them after his passed away. He told them,
I leave you a kingdom, which will be strong if you act honorably, but weak, if you are ill-affected to each other; for by concord even small states are increased, but by discord, even the greatest fall to nothing.10