The year 23 BCE began without incident, but Augustus was now preoccupied by the issue of who would succeed him. The matter came to a head when Augustus, then in his fortieth year, fell ill again and this time it really did seem that he would die.1 He put his affairs in good order and called a meeting of the magistrates, leading senators, certain equites and Agrippa. Those attending and expecting him to announce a successor – specifically Marcellus – were to be disappointed. Overcoming his nausea he talked with them awhile about the state of public affairs. He gave Calpurnius Piso copies of his written documents detailing the strength and locations of the armed forces and a statement of the public revenues.2 Then he handed his signet ring to Agrippa. It may have been intended to simply demonstrate his confidence in his close friend, but others present reasonably inferred a deeper meaning: Agrippa was the heir apparent. Indeed, he would have been a popular choice had that been Augustus’ intention, but the fact of the matter was ‘he did not, to be sure, appoint a successor’.3
Augustus’ health did not improve and he eventually lost the will to attend even to the most urgent matters.4 When the regular therapy of potions and prayers did not work, his personal physician Antonius Musa tried a different approach: a course of cold baths and cold medicines. Remarkably, the treatment worked and Augustus made a full recovery. Musa, a libertus, was handsomely rewarded with cash and certain privileges, including the ability to wear gold rings (normally denied to freedmen), and he was granted exemption from taxes, both for himself and his descendants, and also for the other members of his profession.
When he felt fit enough Augustus attended a session of the Senate in person.5 He went with the express intention of showing that he was alive and well, and in no need of a successor. He took with him his last will and testament but, as a mark of their confidence in his longevity and out of respect for his privacy, the senators would anyway not let him read aloud its contents. The occasion is known to modern historians as the ‘Second Constitutional Settlement’. The Senate now reconfirmed Augustus’ power to govern provinces, but enhanced it as imperium maius, and consented again to his tribunicia potestas, which would thereafter be renewed annually. In return, Augustus resigned the consulship and agreed he would no longer automatically assume the most senior magistracy at the start of the year. Probably at this time Agrippa was granted imperium proconsulare, though it is not explicitly stated so in the sources.6 This time-limited power gave him the authority to delegate duties to the legati personally appointed by Augustus in the imperial provinces.7