What did it mean to be a citizen of ancient Rome?
There were not only sharp divisions in Roman society between citizens and noncitizens, but also a distinct hierarchy of class within the citizen body. As time went on Roman society naturally evolved and became more complex, and this hierarchy evolved along with it.
Like the ancient Greeks before them the Romans considered citizenship a privileged status. Citizenship offered a number of judicial rights and privileges. In the case of adult males, it entailed both the right to vote in citizen assembles and the obligation of military service to the state.
There was a key difference, however, between Greek and Roman citizenship. The rights and privileges of Greek citizenship were granted only to those who were born citizens, but the Romans found it more beneficial to extend Roman citizenship to outsiders and allow them to share its benefits. Usually this was done in return for the loyalty and, in many cases, the military service of those outsiders.
Originally, two groups of Roman citizens had existed since the founding of Rome. The first group were the plebeians, or the plebs. This was the group that included most ordinary Roman citizens, what we would consider the lower and middle classes. Socially, it was the lower of the two orders. It was also by far the larger in size. The second group were the patricians, the leading families of Roman society. This was the Roman upper class, an order of noble families more prestigious and wealthy than the plebeians.
By about the beginning of the third century BC, the patricians had become more distinctly divided into two subgroups. The aristocrats who came to dominate membership in the Roman Senate and important offices of state during came to be known as the senatorial class. The other subgroup, the equestrians, were effectively the gentry of ancient Rome; aristocrats who largely fell into the same wealth bracket as most senators, but were considered a lower tier of Roman nobility because they had far less active participation in Roman politics than the senatorial class.
As the Roman Republic was transformed into the Roman Empire new opportunities for social mobility and advancement were made available. Augustus’ expansion of state bureaucracy offered chances for plebeians to rise to the equestrian order, and equestrians to rise to the senatorial class through imperial service. Augustus’ reform of the Roman army in particular offered noncitizens a new venue to Roman citizenship through army service.
The noncitizens (peregrini in Latin) were people who lived under Roman rule but were not Roman citizens. During the first and second centuries AD the Roman Empire’s total population included far more noncitizens than citizens. Only male citizens were allowed to join the Roman legions, but military service as Roman auxiliaries was open to noncitizen males. After enlisting and serving for 25 years these soldiers and their families would be granted full Roman citizenship with all its legal benefits and privileges. This policy continued to serve as both a road to citizenship for the peregrini and a useful source of recruits for the Roman army until 212 AD, when an imperial decree was passed granting Roman citizenship to all freeborn inhabitants of the empire.