Gaius Caesar
Although when their relationship began is uncertain, Iullus Antonius became a lover of Julia the Elder. Agrippa died in 12 BC and Julia had been forced to marry her stepbrother, Tiberius. Julia's marriage to her stepbrother had become a disaster and she was desperate to divorce him if not satisfy her desires, and Iullus was open to do so. Tiberius had left Rome in 8 BC leaving Julia and her five children by Agrippa, Gaius Caesar, Lucius Caesar, Julia the Younger, Agrippina the Elder, and Agrippa Postumus, in Rome. Julia felt that her children were unprotected and may have approached Iullus to be a protector for her children, especially her two elder sons, Gaius Caesar and Lucius Caesar, who were Augustus' joint heirs.