AD, a thousand equestrians were registered at Cadiz and Padua alone. Equestrians rose through a military career track (tres militiae) to become highly placed prefects and procurators within the Imperial administration. The rise of provincial men to the senatorial and equestrian orders is an aspect of social mobility in the first three centuries of the Empire. Roman aristocracy was based on competition, and unlike later European nobility, a Roman family could not maintain its position merely through hereditary succession or having title to lands. Admission to the higher ordines brought distinction and privileges, but also a number of responsibilities. In antiquity, a city depended on its leading citizens to fund public works, events, and services (munera), rather than on tax revenues, which primarily supported the military. Maintaining one's rank required massive personal expenditures. Decurions were so vital for the functioning of cities that in the later Empire, as the ranks of the town councils became depleted, those who had risen to the Senate were encouraged by the central government to give up their seats and return to their hometowns, in an effort to sustain civic life. In the later Empire, the dignitas ("worth, esteem") that attended on senatorial or equestrian rank was refined further with titles such as vir illustris ("illustrious man"). The appellation clarissimus (Greek lamprotatos) was used to designate the dignitas of certain senators and their immediate family, including women. "Grades" of equestrian status proliferated. Those in Imperial service were ranked by pay grade (sexagenarius, 60,000 sesterces per annum; centenarius, 100,000; ducenarius, 200,000). The title eminentissimus, "most eminent" (Greek exochôtatos) was reserved for equestrians who had been Praetorian prefects. The higher equestrian officials in general were perfectissimi, "most distinguished" (Greek diasêmotatoi), the lower merely egregii, "outstanding" (Greek kratistos). Unequal justice As the republican principle of citizens' equality under the law faded, the symbolic and social privileges of the upper classes led to an informal division of Roman society into those who had acquired greater honours (honestiores) and those who were humbler folk (humiliores). In general, honestiores were the members of the three higher "orders," along with certain military officers. The granting of universal citizenship in 212 seems to have increased the competitive urge among the upper classes to have their superiority over other citizens affirmed, particularly within the justice system. Sentencing depended on the judgment of the presiding official as to the relative "worth" (dignitas) of the defendant: