Iullus Antonius also. Through his half-sister Antonia Minor, he was a maternal uncle of Germanicus, Livilla and the Emperor Claudius. Lastly, he was a paternal great-uncle of the Emperor Caligula, Julia's grandson by Agrippa, and the Empress Agrippina the Younger, Julia's eldest granddaughter, and Claudius' niece and fourth wife, as well as other children fathered by Germanicus and his wife Agrippina the Elder: Nero Julius Caesar, Drusus Caesar, Julia Drusilla, and Julia Livilla. Through Agrippina the Younger, Iullus was a maternal great-great-uncle of the Emperor Nero. Through his half-sister Antonia Major and stepsister Claudia Marcella Minor, he was also great-uncle to Claudius'
Agrippina the Elder ties to the emperor. Historian Richard Alston says it is likely that either Tiberius or Livia were behind the exile of Agrippina's half-sister and the death of Postumus. He notes the death of Agrippina's mother, who starved herself to death amidst her exile in AD 14, linking her death to Tiberius' disdain for her. Agrippina was vocal about her feelings claiming that Germanicus was murdered to promote Drusus the Younger as Tiberius' heir, and worried that the birth of the Younger Drusus' twin sons would displace her own sons in the line of succession. Her fears proved to be unfounded,