The first of these changes was that the _praefecti_ ceased to be drawn as before from among the veteran centurions of the legions. Early in the reign of Claudius the post of _praefectus alae_ disappeared from the career of the _primipili_, who were promoted henceforward to the tribunate of one of the cohorts of Household Troops at Rome.[292] Centurions of lower rank were still advanced to the command of cohorts both in this and the succeeding periods, but such cases are very rare.[293] A trace of the old connexion between the legionary officers and the _militia equestris_ still survives, however, in the regular use of a centurion as _praepositus cohortis_—that is to say, as temporary commander in case of the death or absence of a _praefectus_.[294] The _numeri_, too, were often placed in charge of an ex-centurion bearing this title, an arrangement which was probably called for by the intractable character of these barbarian irregulars.[295] The employment of tribal chiefs as _praefecti_ also became less frequent, as the auxiliary regiments, transferred from one province to another, and recruited from different nationalities, gradually lost their original character. The mutinous officers of the Rhine army, who were doubtless cashiered by Vespasian, were probably the last examples of _praefecti_ drawn from this class. Lastly, the respective rank of the different posts in the _militia equestris_ was finally determined; and the order _praefectus cohortis_—_tribunus legionis_—_praefectus alae_ is hardly ever varied after 70, except that the tribunate of a _cohors miliaria_ sometimes appears in the second place.[296] The result of these changes was that henceforward the auxiliary officers were practically all of one type, men of equestrian rank entering upon what was now the accustomed _cursus honorum_ of their class. That this system was not universally adopted at an earlier date is not surprising. The equestrian _praefecti_ were young men directly appointed by the emperor, without any previous military training; before the auxilia could be entrusted to their charge a certain advance in civilization and tractability had to be made by the provincials, and the veteran centurions and tribal chiefs of the Augustan system were more fitted to deal with the men who composed the auxiliary levies during the first hundred years of the Empire. As it was, these regiments contained in the second century far fewer representatives of the governing class than the native corps in our own Indian army. With the exception of the _praefectus_, who himself was not necessarily an Italian, the officers—that is, the centurions and decurions—were practically all, as we have seen, promoted from the ranks. But to the Roman Empire, in which rulers and ruled, never separated by any deep racial or religious gulf, were gradually made closer akin by the bond of a common civilization, our rule in India affords in this respect no real parallel.