My title is: What was the main purpose of the ephebeia: to become a citizen, a rite of manhood or a preparation for warfare? To explore this question, I examined the institution of the ephebeia, principally the well-known Athenian ephebeia but also other Hellenic examples, with three aspects in mind and in chronological order. The premise of this study was to ascertain the exact purpose of the ephebeia, through three key aspects, spanning from its Classical roots in the 4th century BC, through the Hellenistic era and into the Imperial Roman period, eventually ending sometime in the 4th century AD.