This book investigates the development and combat performance of the Messerschmitt Bf 109D and E variants during the crucial early years of World War II, from 1939 to 1941. Written by John Weal, a recognized authority on Luftwaffe aircraft, the work draws upon extensive archival research and technical documentation to detail the aircraft's design evolution, operational deployment, and its role in pivotal air battles. The central argument focuses on how these early models of the Bf 109 established German air superiority in the initial phases of the conflict and set the stage for future aerial warfare developments.

This book is regarded as a solid, detailed account for aviation enthusiasts and historians interested in early World War II fighter aircraft. The author's expertise in Luftwaffe history lends credibility to the technical and operational analysis presented. The focus on the specific period of 1939-1941 provides a deep dive into a critical phase of aerial combat development.