Octavia, the name of two princesses of the Augustan house. (I) Octavia, daughter of Gaius Octavius and sister of the emperor Augustus, was the wife of Gaius Marcellus, one of the bitterest enemies of Julius Caesar. In 41 B.C. her husband died, and she was married to Marcus Antonius, with the idea of bringing about a reconciliation between him and her brother. Her efforts were at first successful, but in 36 Antony left for the Parthian War and renewed his intrigue with Cleopatra. Though Octavia took out troops and money to him (35), he refused to see her and formally divorced her in 32, but she always protected his children, even those by Fulvia and Cleopatra. Her beauty and virtues are praised by all ancient authorities. By her first husband she was the mother of Marcus Marcellus (q.v.), who died in 23 B.C. (2) Octavia, daughter of the emperor Claudius, was the wife of Nero, by whom she was put to death. A Latin tragedy on her fate is attributed, though wrongly, to Seneca.