This volume investigates the historical accuracy, narrative structure, and political context of the final books of Polybius's 'Histories'. F. W. Walbank, a preeminent scholar of Hellenistic history, utilizes his extensive expertise in ancient Greek historiography to provide a rigorous line-by-line analysis of the surviving fragments and accounts from books XIX through XL. The work serves as a critical apparatus for understanding the transition of the Mediterranean world under Roman hegemony, synthesizing archaeological, epigraphic, and literary evidence to clarify Polybius's complex account of the second century BCE.

Scholars and classicists widely recognize this series as the definitive reference for the study of Polybius. Readers frequently note the academic density of the prose, which is intended for researchers and advanced students of ancient history.