In Greek mythology, Caeneus was originally a Thessalonian woman, Caenis, the daughter of Elatus. She was raped by Poseidon, who then fulfilled her request to be changed into a man so that she could never be raped again; he also made Caeneus invulnerable to weaponry. She changed her name to Caeneus and became a warrior who took part in the hunt for the Calydonian Boar. He died in the battle between the Lapiths and the centaurs (See Pirithous), who piled tree trunks upon him since he was immune to weapons. He flew away from the pile of tree trunks as a bird. Alternatively, he changed back into a woman after death and was buried as a female.
Caenis was born a slave in the palace, but when she was a child, her intelligence was recognized, and she has been well educated so that she can work as a scribe.
It is not only Vespasian who has embarked on the course of honor but Caenis, too, who, in spite of her lower rank, is a person of rare nobility of character while most of the nobility were of the lowest rank of morality.
Caenis and Vespasian aren't cut from the usual he's-handsome-she's-beautiful hero and heroine mold that romance readers are familiar with.