The Battle of Britain, Winston Churchill famously remarked, was the "finest hour" of the Royal Air Force, which battled Hitler's Luftwaffe in the skies above England for a few tense weeks. That storied episode, which historian Richard Overy deems a stalemate rather than a decisive triumph, has been layered with legends, one being that the RAF's determined resistance was the key factor in repelling an impending Nazi invasion. It now appears that that was never a real possibility. Another legend was that the RAF was badly outnumbered and outgunned. In fact, as Overy details, the German and British air forces were fairly evenly matched, and the RAF sustained fewer losses than it delivered. Overy's slender, well-written study of the Battle of Britain celebrates the very real accomplishments of the RAF and, its revisionism aside, acknowledges that the Battle of Britain was a true turning point in the history of World War II. Overy holds that one of its most important results was to lead influential Americans to urge that the United States take Britain's side, a fact that would soon be realized. More important, though, the Battle of Britain kept England in the war at a time when many politicians and citizens sought some accommodation with the Nazi regime. It galvanized popular opposition to Hitler, replacing uncertainties and disagreements with "a greater sense of purpose and a more united people." --Gregory McNamee