Josiane Rittevon is a princess of the the Copper Isles who appears in Lioness Rampant. Queen Lianne, a childhood friend of her mother's, encourages Jonathan to court Josiane. Their relationship is brief and not elaborated upon; Jonathan ends it when he realizes Josiane is a cruel person.
Josiane becomes attached to Delia of Eldorne, and through her to Roger of Conté. During the Coronation Day Battle she attacks Alanna with an axe and successfully kills Faithful and Master Si-cham, and is then killed by Alanna.
She is mentioned casually by Joren of Stone Mountain in First Test; he postulates that the Immortals War was caused by bad blood between Tortall and the Copper Isles, attributable to Alanna's killing of a Rittevon princess. Aly mentions her twice during Trickster's Choice and Trickster's Queen, once as King Oron's niece and once as his daughter.