So in AD 4 Tiberius, son of Livia, stepson of Augustus, was adopted into the Julius family and had only Augustus’ unsatisfactory grandson, Postumus, between him and the prospect of ruling Rome. AUGUSTUS LOVES LIVIA. But Augustus didn’t love Tiberius that much and he had not finished with the DADS ARE BEST principle. He soon rejected Postumus and was left with the prospect of Tiberius taking over, and founding his own dynasty, with no biological connection to Augustus at all. Yet there were still options among his biological family through his sister’s daughters.
Essentially, Augustus had a good stepson/bad stepson problem, at least, from his own point of view. Livia’s younger son, Drusus, was the good stepson. He had never known any father except Augustus – and many people believed he was Augustus’ son, conceived while Livia was still married to her previous husband. He was a great military commander in his own right, and earned the title Germanicus for his family in battle. And he had married a daughter of Augustus’ sister Octavia in 16 BC.
In 16 BC this had made sense. Julia 1 (GIRLS ARE MUMS) and Agrippa were producing numerous children, including the boys, Gaius and Lucius. Tiberius had been betrothed to Vipsania, Agrippa’s daughter by a previous marriage, almost since she was born – a political match which had nothing to do with the succession. They married in 19 BC and were happy. Meanwhile, as a back-up plan for the succession, Augustus decided Drusus could be a father of his own father’s descendants (DADS ARE BEST) and married him to his niece, the daughter of his sister Octavia in 16 BC. While this fulfilled the AUGUSTUS LOVES LIVIA principle, Augustus didn’t expect to need either of Livia’s sons in the succession.
All this changed with Agrippa’s death in 12 BC, Tiberius’ disastrous marriage to Augustus’ daughter, Julia 1, and her disgrace and exile. Augustus had to give up on having a biological grandson in the line of succession. But Drusus’ successful marriage had produced a potential heir, descended through women from Augustus’ biological father Gaius Octavius . This new arrival was – well, he is always called Germanicus.
If Drusus had lived, Tiberius would almost certainly have missed out on the succession in AD 4. He and Augustus had had a terrible relationship since the marriage to Julia in 11 BC. Drusus could have been adopted as a strong successor and caretaker for his own son, Germanicus. But Drusus died in 9 BC, reputedly of falling off a horse – another example of the dangers of campaign. Left without Drusus, Augustus briefly considered making Germanicus his heir, but at barely twenty, he was too young to take over, especially against the opposition of his now wicked uncle, Tiberius.
But the future was with Germanicus. Let’s not forget Julia 1’s daughters (GIRLS ARE MUMS). By now, Augustus had given up on marrying Tiberius to anybody. But Julia’s daughters were still available for marriages and their children would be great grandchildren to Augustus himself. He was set on Germanicus, already a great nephew via Octavia, marrying one of Julia’s daughters and fathering his great grandchildren. So Augustus came up with a complicated plan.
In AD 4 Augustus forced Tiberius to adopt Germanicus, his nephew and to make him his heir above his own son. Augustus finished the plan by marrying Germanicus to one of Julia’s daughters, Agrippina. Now everything would unfold as if Drusus had lived, with Tiberius filling in until Drusus’ son took over.
Augustus was following the four principles.
Germanicus (DADS ARE BEST) was descended from Augustus’ father, Gaius Octavius, through Octavius’ daughter Octavia, and her daughter Antonia (GIRLS ARE MUMS). So he was descended both from Livia on the one side (AUGUSTUS LOVES LIVIA) and Augustus’ father on the other. By the marriage to Agrippina, Augustus’ granddaughter, Germanicus’ children could be descended from Augustus himself. So Germanicus’ children would be Augustus’ descendants, Gaius Octavius’ descendants, and also Livia’s descendants in a mixed Julio-Claudian succession. As a promising young commander, Germanicus would soon be able to ensure the NO MORE WAR principle for himself. And meanwhile Tiberius would be get to rule for life, but he would not get to found a dynasty. All this might have made sense on paper, but it took no account of psychology.
What about Tiberius’ son? Well, like Tiberius, Tiberius’ son wasn’t biologically connected with Augustus at all. He had a place in the succession too – Tiberius was allowed to adopt him as a Julian and junior heir after Germanicus. And a marriage was made between Tiberius’ son and Germanicus’ sister. This gave Augustus another chance to bring his father’s line into the succession even if Germanicus died without heirs. After Tiberius would come his son (unrelated to Augustus) and then his son (descended from Augustus’ father). But Germanicus and his line came first.
Tiberius came off worst in these arrangements. having been forced to divorce his son’s mother to marry Julia 1, he now found his son virtually disinherited. He had to treat his nephew, Germanicus, as senior in his household to his own son – a humiliating position. And he became a wicked uncle to Germanicus, knowing that his own son could only succeed if Germanicus’ line failed. When Augustus made these arrangements, he was signing a death warrant for his granddaughter Agrippina and two of her sons, who would be wiped out, along with other potential rivals, in the reign of Tiberius. Germanicus himself would die of poisoning on campaign in 19 AD. But Germanicus would eventually contribute two Emperors to the succession – his son Caligula and grandson Nero.
We are now ready for the final post; Part 9 – Swapping Off.