Paedagogi
In the Roman Republic, the paedagogus, plural paedagogi or paedagogiani, was a slave or a freedman who taught the sons of Roman citizens the Greek language. In the period of the Roman Empire, the "paedagogus" became the director of the "paedagogium". In the early Republic, there were no public schools, so boys were taught to read and write by their parents, or by educated slaves ("paedagogi") usually of Greek origin. A representation of a "paedagogus" was painted as a graffiti on the walls of the Palatine Paedagogium, and it represents his social and cultural formation, which is identified such  a slave. In an inscription of the second century dedicated to the Roman emperor Caracalla, it lists twenty-four "paedagogi". In some cases, the title of "paedagogus" is connected with private elite families. Being a "paedagogus" meant to obey conduct and duty laws. In the imperial institution, the title of "paedagogus" refers to the duty of child-attendant or tutor rather than a teacher. The other title of "paedagogus" refers to a variety of interrelated capacities related to the offspring of the imperial family and aristocracy: "disciplina" (academic and moral instruction), "custodia" (companion and protector) and "decorum" (directives of precepts  for public behaviour). There is a third title which appears in three inscriptions and means the director of the "paedagogium" ("praeceptor"). In other texts and graphics, slaves are divided depending on their membership of a larger servile environment ("paedagogium"), freedpersons ("paedagogi", "paedagogiani", "custodes" and "procuratores") and a community of persons ("pueri", "iuvenes", "vernae domini nostri").