Developed as a private venture, the P-51 was seized upon by the British as the answer to their shortage of fighter aircraft in the early months of World War II. Early Allison-engined Mustangs lacked performance at high altitude, but the great promise of the airframe was clear, and when fit-ted with the Rolls-Royce Merlin, the Mustang became one of the best piston engine fighters ever built. Not only was its performance on a par with the best British and German fighters, but it was the first single-engine fighter with range sufficient to accompany bombers from Great Britain to Ber-lin and back. This new history of the Mustang tells the full story of its development, technical fea-tures and operational history, and also looks at its long post-war career as warbird and racer.