Volume Two of Dio Cassius brings to a close his sweeping historical work, Roman History. This volume begins with book 50 and the struggle between Octavian and Mark Antony. Octavian's victory is the beginning of the Principate and a new direction in Roman history. Dio takes a prolonged look at the reign of Augustus. He follows this with the history of the following emperors: Tiberius, Gaius (Caligula), Claudius, Nero, Galba, Otho, Vitellius, Vespasian, Titus, Domitian, Nerva, Trajan, Hadrian, Antoninus Pius, Lucius Verus, Marcus Aurelius, Commodus, Pertinax, Didius Julianus, Septimius Severus, Caracalla, Geta, Macrinus, Diadumenian, Elagabalus, and Alexander Severus. Much of our information about the emperors who followed Commodus is only available in the work of Dio Cassius. Please note that book 72 is no longer extant.