Octavia the Younger (; c. 66 BC – 11 BC) was the elder sister of the first Roman Emperor, Augustus (known also as Octavian), the half-sister of Octavia the Elder, and the fourth wife of Mark Antony. She was also the great-grandmother of the Emperor Caligula and Empress Agrippina the Younger, maternal grandmother of the Emperor Claudius, and paternal great-grandmother and maternal great-great-grandmother of the Emperor Nero. One of the most prominent women in Roman history, Octavia was respected and admired by contemporaries for her loyalty, nobility and humanity, as well as for maintaining traditional Roman feminine virtues. Life Childhood Octavia was born around 66 BC. Full sister to Augustus, Octavia was the only daughter born of Gaius Octavius' second marriage to Atia, niece of Julius Caesar. Octavia was born in Nola, present-day Italy; her father, a Roman governor and senator, died in 59 BC from natural causes. Her mother later remarried, to the consul Lucius Marcius Philippus. Octavia spent much of her childhood travelling with her parents. Marcius was in charge of educating Octavia and her brother Octavian, later known as Augustus. First marriage Some time before 54 BC, her stepfather arranged for her to marry Gaius Claudius Marcellus. Marcellus was a man of consular rank, a man who was considered worthy of her and was consul in 50 BC. He was also a member of the influential Claudian family and descended from Marcus Claudius Marcellus, a famous general in the Second Punic War. In 54 BC, Octavia's great-uncle Julius Caesar is said to have been anxious for her to divorce her husband so that she could marry Pompey, who had just lost his wife Julia (Caesar's daughter, and thus Octavia's cousin once removed). The couple did not want to get a divorce, so instead Pompey declined the proposal and married Cornelia Metella. Thus, Octavia's husband continued to oppose Julius Caesar, including in the crucial year of his consulship, 50 BC. Civil war broke out when Caesar invaded Italy from Gaul in 49 BC. Marcellus, a friend of Cicero, was an initial opponent of Julius Caesar when Caesar invaded Italy, but did not take up arms against his wife's great uncle at the Battle of Pharsalus, and was eventually pardoned by him. In 47 BC he was able to intercede with Caesar for his cousin and namesake, also a former consul, then living in exile. Presumably, Octavia continued to