68–9). Otherwise, usurpation attempts by provincial governors were few and swiftly suppressed. As regards the military, members of the senatorial order (senatorii) exclusively filled the following posts: (a) legatus Augusti pro praetore (provincial governor of a border province, who was commander-in-chief of the military forces deployed there as well as heading the civil administration) (b) legatus legionis (legion commander) (c) tribunus militum laticlavius (legion deputy commander). The equites provided: (a) the governors (procuratores) of Egypt and of a few minor provinces (b) the two praefecti praetorio (commanders of the Praetorian Guard) (c) a legion's praefectus castrorum (3rd-in-command) and its remaining five tribuni militum (senior staff officers) (d) the praefecti (commanders) of the auxiliary regiments. By the late 1st century, a distinct equestrian group, non-Italian and military in character, became established. This was a result of the established custom whereby the emperor elevated the primuspilus (chief centurion) of each legion to equestrian rank on completion of his year in office. This resulted in some 30 career soldiers, mostly non-Italian and risen from the ranks, joining the aristocracy each year. Far less wealthy than their Italian counterparts, many such equites belonged to families that provided career soldiers for generations. Prominent among them were Romanised Illyrians, the descendants of the Illyrian-speaking tribes that inhabited the Roman provinces of Pannonia (W Hungary/Croatia/Slovenia), Dalmatia (Croatia/Bosnia) and Moesia Superior (Serbia), together with the neighbouring Thracians of Moesia Inferior (N Bulgaria) and Macedonia provinces. From the time of Domitian (81–96), when over half the Roman army was deployed in the Danubian regions, the Illyrian and Thracian provinces became the most important recruiting ground of the auxilia and later the legions. 3rd-century developments The seminal development for the army in the early 3rd century was the Constitutio Antoniniana (Antonine Decree) of 212, issued by Emperor Caracalla (211–217). This granted Roman citizenship to all free inhabitants of the empire, ending the second-class status of the peregrini. This had the effect of breaking down the distinction between the citizen legions and the auxiliary regiments. In the 1st and 2nd centuries, the legions were the symbol (and guarantors) of the dominance of the Italian "master nation" over its subject peoples. In the 3rd century, they were no longer socially superior to their auxiliary counterparts (although they may have retained their elite status in military terms) and the legions' special armour and equipment (e.g. the lorica segmentata) was phased out. The traditional