Episode 186 of Marcus Aurelius: Rome's Philosopher King turns the spotlight on Annia Galeria Faustina Minor — the emperor's wife, mother of his thirteen children, and the most controversial woman of the second century. We explore her youth as daughter of Antoninus Pius, her marriage to Marcus, her influence in the palace and on campaign, and the dark rumors that followed her: infidelity, conspiracy with Avidius Cassius, even suicide. Drawing on Cassius Dio, the Historia Augusta, and the coinage that celebrated her as 'Mater Castrorum' (Mother of the Camp), we separate legend from evidence. Lucas and Luna consider how Marcus's Stoic principles shaped his unwavering defense of Faustina, and how her legacy outlived both of them — through colonies like Faustinopolis, and through the daughter who would try to overthrow her own brother Commodus.