The illness of Augustus in 23 BC brought the problem of succession to the forefront of political issues and the public. To ensure stability, he needed to designate an heir to his unique position in Roman society and government. This was to be achieved in small, undramatic, and incremental ways that did not stir senatorial fears of monarchy. If someone was to succeed his unofficial position of power, they were going to have to earn it through their own publicly proven merits.
Some Augustan historians argue that indications pointed toward his sister's son Marcellus, who had been quickly married to Augustus' daughter Julia the Elder. Other historians dispute this due to Augustus' will read aloud to the Senate while he was seriously ill in 23 BC, instead indicating a preference for Marcus Agrippa, who was Augustus' second in charge and arguably the only one of his associates who could have controlled the legions and held the Empire together.
After the death of Marcellus in 23 BC, Augustus married his daughter to Agrippa. This union produced five children, three sons and two daughters: Gaius Caesar, Lucius Caesar, Vipsania Julia, Agrippina the Elder, and Postumus Agrippa, so named because he was born after Marcus Agrippa died. Shortly after the Second Settlement, Agrippa was granted a five-year term of administering the eastern half of the Empire with the imperium of a proconsul and the same tribunicia potestas granted to Augustus (although not trumping Augustus' authority), his seat of governance stationed at Samos in the eastern Aegean. Although this granting of power would have shown Augustus' favor for Agrippa, it was also a measure to please members of his Caesarian party by allowing one of their members to share a considerable amount of power with him.
Augustus' intent to make Gaius and Lucius Caesar his heirs was apparent when he adopted them as his own children. He took the consulship in 5 and 2 BC so he could personally usher them into their politica...