labour shortage. The steady exodus of both rich and poor from the cities and now-unprofitable professions forced Diocletian to use compulsion; conscription was made universal, most trades were made hereditary, and workers could not legally leave their jobs or travel elsewhere to seek better-paying ones. This included the unwanted middle-class civil service positions and under Constantine, the military. Constantine also tried to provide social programs for the poor to reduce the labour shortage. Increased militarization All the barracks emperors based their power on the military and on the soldiers of the field armies, not on the Praetorians in Rome. Thus, Rome lost its role as the political center of the empire during the third century, although it remained ideologically important. In order to legitimize and secure their rule, the emperors of the third century needed above all military successes. The centre of decision-making shifted away from Rome and to wherever the emperor was with his armies, typically, in the east. This led to the transfer of the capital to the four cities Milan, Trier, Nicomedia, and Sirmium, and then to Constantinople. The Senate ceased to be the main governing organ and instead members of the equestrian class who filled the military officer corps became increasingly prominent. Emperors Several emperors who rose to power through acclamation of their troops attempted to create stability by giving their descendants the title of Augustus and so making them co-emperors who later succeeded to the throne after their death or on some occasions their relatives managed to become an emperor immediately after their death. This led to the creation of several brief dynasties. Non-dynastic Gordian dynasty Non-dynastic Decian dynasty Non-dynastic Valerian dynasty Claudian dynasty Non-dynastic Tacitan dynasty Non-dynastic Caran dynasty See also Bagaudae Sengoku period – a similar period in Japanese history Warring States period and Three Kingdoms period – similar periods in Chinese history Jublains archeological site documents some effects of the crisis in what is now western France Citations General bibliography Olivier Hekster, Rome and Its Empire, AD 193–284 (Edinburgh, 2008). . Klaus-Peter Johne (ed.), Die Zeit der Soldatenkaiser (Akademie Verlag, Berlin 2008). Lot, Ferdinand. End of the Ancient World and the Beginnings of the Middle Ages (Harper Torchbooks Printing, New York, 1961. First English printing by Alfred A. Knopf, Inc., 1931). Moss, H. St. L. B. The Birth of the Middle Ages (Clarendon Press, 1935, reprint Oxford University Press, January 2000). .