Ephēboi originally meant boys who had reached the age of puberty, and was one of several terms for age classes; but in 4th-cent. bce Athens it came to have a special paramilitary sense, boys who in their eighteenth year had entered a two-year period of military training. In the first year they underwent, in barracks in Piraeus, training by paidotribai (physical trainers) and technical weaponry instructors, all under the general supervision of a kosmētēs and of ten (later twelve) sōphronistai, one from each of the tribes (phylai). In the second year they served at the frontier posts of Attica as peripoloi. They may have had ritual duties.

Despite the military amateurism of which Thucydides (2) makes Pericles (1) boast in the surprising ch. 2. 39, it is unlikely that there was no system of training before the 4th cent., and traces of the later ‘oath of the ephebes’ (RO no. 88) have been detected in e.g. Thucydides (2) and Sophocles (1). And structuralist accounts of the ephebate bring out its (ancient?) function as a rite of passage; they point to the marginal character of service on the frontiers and to the civic exemptions and exclusions to which ephebes were subject, i.e. ephebes were made non-hoplites in preparation for being real hoplites. But it is agreed that there is no hard evidence for a formal ephebic system before the mid-330s when Epicrates introduced a law about it (Harpocration, entry under ‘Epikrates’). Certainly no ephebic inscription has yet been found dated securely to before 334.

From the 3rd cent. bce the ephēbeia, based on the gymnasium, was a universal feature of the polis; the usual assumption, that Athens provided the model, is probably exaggerated. The institution flourished for as long as the polis: in Paphlagonia it was still being introduced under Commodus (IGRom. 3. 1446). Attested at Oxyrhynchus as late as ce 323 (POxy. 42), its final disappearance in the 4th cent. reflects the depleted finances of the late Roman city and the eventual devaluation of physical education.

The Athenian ephēbeia ceased to be compulsory in 305 bce and from 282 bce service was reduced to one year; thereafter, there and elsewhere, it increasingly resembled an association for young ‘gentlemen’, with a (superficial) intellectual training (notably classes in philosophy, letters, rhetoric, and music are attested) coming to supplement athletics and arms-drill. This tendency towards pacifism (a function of the decreased importance of civic militia), although widely found, was not universal: in Macedonia, where a ‘national’ army underpinned the monarchy, ephebes performed only military exercises down to 168 bce; at Sparta archaism explains the unusually long-lived emphasis on rough team-sports. See agoge.

The post-Classical ephēbeia was a civic instrument for relaying a basic and, on the whole, surprisingly uniform cultural Hellenism to the rising generation; it functioned too as a definer of social status (a role institutionalized in Roman Egypt, where ‘those from the gymnasium’ enjoyed tax-perks) and as a transmitter of civic tradition and identity through ephebic participation in local festivals, agōnes, and cults (as shown by G. Rogers for Roman Ephesus). And, not least, it was a means of containing the potential rowdiness of youth (see Ἔργον‎1984, 23 for an ephebic law of 24/3 bce requiring ephebes in the theatre ‘not to clap, nor hiss, but to watch silently and decorously’). See education, greek and roman; gymnasiarch.