History of the Roman Empire founder of the brief Flavian dynasty, to be followed by the Nerva–Antonine dynasty which produced the "Five Good Emperors": Nerva, Trajan, Hadrian, Antoninus Pius and the philosophically inclined Marcus Aurelius. In the view of the Greek historian Dio Cassius, a contemporary observer, the accession of the emperor Commodus in 180 AD marked the descent "from a kingdom of gold to one of rust and iron"—a famous comment which has led some historians, notably Edward Gibbon, to take Commodus' reign as the beginning of the decline of the Roman Empire. In 212, during the reign of Caracalla, Roman citizenship was granted
History of the Roman Empire empire for forty years, and was succeeded as emperor by Tiberius. The Augustan Age is not as well documented as the age of Caesar and Cicero. Livy wrote his history during Augustus's reign and covered all of Roman history through 9 BC, but only epitomes survive of his coverage of the late Republican and Augustan periods. Important primary sources for the Augustan period include: Works of poetry such as Ovid's "Fasti" and Propertius's Fourth Book, legislation and engineering also provide important insights into Roman life of the time. Archaeology, including maritime archaeology, aerial surveys, epigraphic inscriptions on buildings, and Augustan