His earliest memories are his boyhood years in Italica. He also talks of his early interest in astrology and his lifelong passion for the arts, culture, and philosophy of Greece; themes which he revisits throughout the book. He visits Athens to study, travels to Rome for the first time, and witnesses the accession of Trajan. He eventually joins the army and participates in the Dacian campaign. Hadrian, who is around thirty years old at the end of the war, describes his successes in the army and his relationship with Trajan who is initially cold towards him. He slowly gains Trajan's favor and secures his position for the throne with the help of Plotina, the emperor's wife, and also by marrying Sabina, Trajan's grandniece.