This collection of lectures investigates the origins, linguistic evolution, and cultural significance of early Welsh poetic traditions. Sir Ifor Williams, a preeminent scholar of Celtic studies, utilizes his extensive expertise in Old and Middle Welsh to reconstruct the historical context of the earliest surviving verse. The work provides a rigorous philological framework for understanding the transition from oral tradition to written manuscript, arguing for the continuity of Welsh literary identity across the early medieval period.

This work is regarded as a foundational text in the field of Celtic philology, noted for its meticulous scholarship and rigorous linguistic methodology. The text serves as an essential reference for specialists and students seeking to understand the complexities of early Welsh literary history.