 <unk> 's mother was <unk> the Younger , a great @-@ granddaughter of Caesar Augustus and his wife <unk> through their daughter Julia the Elder and her husband Marcus <unk> <unk> . <unk> 's father , <unk> , was a grandson of Augustus 's wife , <unk> , on one side and to Mark Antony and Octavia on the other . <unk> ' mother <unk> Minor , was a daughter of Octavia Minor and Mark Antony . Octavia was Augustus ' elder sister . <unk> was also the adopted son of <unk> . <unk> poisoned her second husband <unk> <unk> , so many ancient historians also accuse her of murdering her third husband , the emperor Claudius . 
