The Nuttall Encyclopedia
The sister of Augustus, a woman distinguished for her beauty and her virtue; was married first to Marcellus, and on his death to Mark Antony, who forsook her for Cleopatra, but to whom she remained true, even, on his miserable end, nursing his children by Cleopatra along with her own; one other grief she had to endure in the death of her son Marcellus (q. v .) by her former husband, and the destined successor of Augustus on the throne.
Wood, James, ed. Entry for 'Octavia'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/o/octavia.html. Frederick Warne & Co Ltd. London. 1900.