The book constitutes an in-depth analysis of the work Περὶ Αἰολίδος by the Byzantine grammarian Gregory of Corinth in the context of current research on the origin and development of the Lesbian dialect. The book represents a significant contribution not only to the study of the ancient Greek language but also encourages reflection on the processes that shaped the linguistic and grammatical tradition of ancient Greece. By confronting Gregory's text with authentic dialectal material, the author sheds new light on the relationships between different types of sources and also introduces interpretations of dialectal material attributed to the Aeolians by ancient tradition. The author meticulously analyses the quoted data in terms of its actual dialectal nature, emphasizing the possible reasons why the grammatical tradition identified specific examples as illustrations of the Lesbian dialect.