A somewhat less rapid but in the end not less complete decadence had taken place in military life. The Roman army was at first recruited exclusively from the upper classes, and the service, which lasted only during actual warfare, was gratuitous. Before the close of the Republic, however, these conditions had disappeared. Military pay is said to have been instituted at the time of the siege of Veii.(451) Some Spaniards who were enrolled during the rivalry of Rome and Carthage were the first example of the employment of foreign mercenaries by the former.(452) Marius abolished the property qualification of the recruits.(453) In long residences in Spain and in the Asiatic provinces discipline gradually relaxed, and the historian who traced the progress of Oriental luxury in Rome dwelt with a just emphasis upon the ominous fact that it had first been introduced into the city by soldiers.(454) The civil wars contributed to the destruction of the old military traditions, but being conducted by able generals it is probable that they had more effect upon the patriotism than upon the discipline of the army. Augustus reorganised the whole military system, establishing a body of soldiers known as the Prætorian guard, and dignified with some special privileges, permanently in Rome, while the other legions were chiefly mustered upon the frontiers. During his long reign, and during that of Tiberius, both sections were quiescent, but the murder of Caligula by his soldiers opened a considerable period of insubordination. Claudius, it was observed, first set the fatal example of purchasing his safety from his soldiers by bribes.(455) The armies of the provinces soon discovered that it was possible to elect an emperor outside Rome, and Galba, Otho, Vitellius, and Vespasian were all the creatures of revolt. The evil was, however, not yet past recovery. Vespasian and Trajan enforced discipline with great stringency and success. The emperors began more frequently to visit the camps. The number of the soldiers was small, and for some time the turbulence subsided. The history of the worst period of the Empire, it has been truly observed, is full of instances of brave soldiers trying, under circumstances of extreme difficulty, simply to do their duty. But the historian had soon occasion to notice again the profound influence of the voluptuous Asiatic cities upon the legions.(456) Removed for many years from Italy, they lost all national pride, their allegiance was transferred from the sovereign to the general, and when the Imperial sceptre fell into the hands of a succession of incompetent rulers, they habitually urged their commanders to revolt, and at last reduced the empire to a condition of military anarchy. A remedy was found for this evil, though not for the luxurious habits that had been acquired, in the division of the empire, which placed each army under the direct supervision of an emperor, and it is probable that at a later period