The present paper investigates the earliest epigraphical evidence for spirantization of the Ancient Greek voiced stop series /b d g/ in the different dialects. In the introduction (§1), the issue at hand is presented: does the earliest extant evidence of spirantization point to the introduction of a new series of fricative phonemes, or to mere context-sensitive fricative variants of allophonic rather than phonemic status? This question is answered through a re-evaluation of the evidence cited in earlier scholarship (§2). The investigation leads to the conclusion (§3) that spirantization was of allophonic status in most dialects, and that we are dealing with a phenomenon which was widespread already in the Archaic period.