Nero 's mother was Agrippina the Younger , a great @-@ granddaughter of Caesar Augustus and his wife Scribonia through their daughter Julia the Elder and her husband Marcus Vipsanius Agrippa . Agrippina 's father , Germanicus , was a grandson of Augustus 's wife , Livia , on one side and to Mark Antony and Octavia on the other . Germanicus ' mother Antonia Minor , was a daughter of Octavia Minor and Mark Antony . Octavia was Augustus ' elder sister . Germanicus was also the adopted son of Tiberius . Agrippina poisoned her second husband Passienus Crispus , so many ancient historians also accuse her of murdering her third husband , the emperor Claudius .