Motorcycles entered military service in World War I, replacing the mounted despatch rider and mechanizing machine-gun and stretcher units. The conflict brought an enormous upsurge in the use of motorcycles in Europe and America. This comprehensive new book covers the lively history of the machines, highlighting the roles of military motorcycles, and how they have evolved. An A-Z directory focuses on 160 motorcycles, showing their diversity. Detailed specification boxes are featured for every motorcycle described. This expertly written book, with its wealth of rare and previously unseen photographs, provides enthusiasts and historians with key information about these diverse and multi-tasking vehicles.