Octavia (ŏktāˈvēə) [key]. 1 d. 11 B.C., Roman matron, sister of Emperor Augustus and wife of Marc Antony, her second husband. For some years, she helped maintain peace between her brother and her husband. Antony fell in love with Cleopatra, and after his war with Augustus began, he divorced (32 B.C.) Octavia. After his death, she reared his children by Fulvia (his first wife) and by Cleopatra, as well as her own. 2 d. A.D. 62, Roman matron, daughter of Emperor Claudius I and Messalina and wife of Nero, whom she married in A.D. 53. Nero deserted her for Poppaea Sabina and divorced her. She was falsely accused of adultery, banished to Pandataria (Ventotene), an island in the Bay of Naples, and put to death. She is the subject of Octavia, a unique contemporaneous tragedy, erroneously attributed to Seneca.