the later Julian emperors, as he was more explicit than any of his predecessors in taking powers that he did not legally have, and in disregarding the constitution. He was killed in 192. No further constitutional reforms were enacted during the Principate. The only development of any significance was the continuing slide towards monarchy, as the constitutional distinctions that had been set up by Augustus lost whatever meaning that they still had. Starting in 235, with the reign of the barbarian emperor Maximinus Thrax, the empire was put through a period of severe military, civil, and economic stress. The crisis arguably reached its height during the reign of Gallienus, from 260 to 268. The crisis ended with the accession of Diocletian in 284, and the abolishment of the Principate. See also Roman Kingdom Roman Republic Roman Empire Roman Law Plebeian Council Centuria Curia Roman consul Praetor Roman censor Quaestor Aedile Roman Dictator Master of the Horse Cursus honorum Byzantine Senate Pontifex Maximus Princeps senatus Interrex Promagistrate Acta Senatus Notes References Further reading Cambridge Ancient History, Volumes 9–13. Cameron, A. The Later Roman Empire, (Fontana Press, 1993). Crawford, M. The Roman Republic, (Fontana Press, 1978). Gruen, E. S. "The Last Generation of the Roman Republic" (U California Press, 1974) Ihne, Wilhelm. Researches Into the History of the Roman Constitution. William Pickering. 1853. Johnston, Harold Whetstone. Orations and Letters of Cicero: With Historical Introduction, An Outline of the Roman Constitution, Notes, Vocabulary and Index. Scott, Foresman and Company. 1891. Millar, F. The Emperor in the Roman World, (Duckworth, 1977, 1992). Mommsen, Theodor. Roman Constitutional Law. 1871–1888 Polybius. The Histories Tighe, Ambrose. The Development of the Roman Constitution. D. Apple & Co. 1886. Von Fritz, Kurt. The Theory of the Mixed Constitution in Antiquity. Columbia University Press, New York. 1975. External links Cicero's De Re Publica, Book Two Rome at the End of the Punic Wars: An Analysis of the Roman Government; by Polybius Considerations on the Causes of the Greatness of the Romans and their Decline, by Montesquieu The Roman Constitution to the Time of Cicero What a Terrorist Incident in Ancient Rome Can Teach Us Government of the Roman Empire Constitutions of ancient Rome