Incest of unequal gravity: the "incestus iuris gentium," which was applied to both Romans and non-Romans in the Empire, and the "incestus iuris civilis," which concerned only Roman citizens. Therefore, for example, an Egyptian could marry an aunt, but a Roman could not. Despite the act of incest being unacceptable within the Roman Empire, Roman Emperor Caligula is rumored to have had sexual relationships with all three of his sisters (Julia Livilla, Drusilla, and Agrippina the Younger). Emperor Claudius, after executing his previous wife, married his brother's daughter Agrippina the Younger, and changed the law to allow an otherwise illegal union.
Agrippina the Elder the soldiers to deal with the ringleaders, which they did with brutal severity. He then led them against the Germanic tribes, perhaps in an effort to prevent future mutiny. Germanicus would remain in Gaul fighting against the Germanic tribes until AD 16, at which time he was recalled to Rome by Tiberius. His campaigns won him much renown among the Roman people, and he was awarded a triumph on 26 May AD 17. In AD 18, Agrippina left for the eastern provinces with her family. Germanicus was sent the east to govern the provinces, the same assignment her father was