This audiobook is narrated by a digital voice.

On September 1, 1939, German forces crossed the Polish border in a coordinated assault that would demonstrate to the world a revolutionary new form of warfare. The invasion of Poland marked not only the beginning of World War II but also the first full-scale deployment of the German military doctrine known as Blitzkrieg, or lightning war. This doctrine, which emphasized speed, coordination, and the concentration of force at decisive points, would transform the nature of modern warfare and enable Germany to achieve a series of stunning victories that brought much of Europe under Nazi control within two years.

The German military machine that launched this campaign was the product of years of careful planning and preparation that had begun almost immediately after Adolf Hitler's rise to power in 1933. Despite the restrictions imposed by the Treaty of Versailles, which had limited Germany to a small professional army and prohibited the possession of tanks, aircraft, and other modern weapons, German military leaders had never abandoned their commitment to rebuilding their nation's military power. Through secret training programs, technological development disguised as civilian research, and careful study of military innovations from other nations, the German armed forces had prepared for the day when they could once again project power beyond their borders.

The Polish campaign revealed the devastating effectiveness of German military innovation and planning. Traditional military wisdom had emphasized the importance of continuous front lines, methodical advances, and the gradual wearing down of enemy resistance through attrition. The German approach rejected these conventional concepts in favor of rapid penetration by combined arms forces that could bypass enemy strongpoints and disrupt command and control systems before defenders could respond effectively.