The Autobiographies are a series of personal writings by Marcus Aurelius, Roman Emperor from 161 to 180 AD, recording his personal notes to himself and his ideas about Stoic philosophy. Marcus Aurelius wrote his 12 books, "Ta ei oun" in the Hellenistic community as a resource for his own guidance and self-improvement. It is possible that large parts of the work were written at Sirmium, where he spent much time planning military campaigns from 170 to 180. Some of it was written while Aquincum was on campaign in Pannonia, because the internal notes tell us that the first book was written when he campaigned against the Kvati on the Granova River (present-day Hron), and the second book was written at Carnudo.