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
Fall of the Western Roman Empire Nepos in 480. Gibbon gave a classic formulation of reasons why the Fall happened. He began an ongoing controversy by attributing a significant role to Christianity in the Western Roman Empire's fall, which is no longer accepted by modern Roman historians. However, he did give great weight to other causes of internal decline as well and to the attacks from outside the Empire. Alexander Demandt enumerated 210 different theories on why Rome fell, and new ideas have emerged since. Historians still try to analyze the reasons for loss of political control over a vast territory (and, as a subsidiary theme,