 The last Republican Civil War would mark the beginning of the Pax Romana, a period of relative internal peace and stability.Mark Antony was in Egypt with Cleopatra instead of his wife, Octavia, who also happened to be Octavian's sister.Octavian was scheming to find a way to sever ties with Antony, start a war to crush him, kill a potential rival (Caesar and Cleopatra’s son, Caesarion), and take control of the entire Roman world.