Blitzkrieg, the German word for "lightning war." There was some mention of the word at the time of the Spanish Civil War (193739), but it did not come into common use in English until the German conquest of Poland in 1939, the beginning of World War II.

German tanks and airplanes led their blitzkrieg attacks.

German forces attacking Poland used fast, hard-hitting tank units, aided by dive bombers, to break through the enemy's defenses and to open gaps for motorized infantry to pour through. The object was to attack so swiftly and penetrate so deeply that the enemy would be unable to recover.

In the spring of 1940 the Germans successfully employed their blitzkrieg tactics against the Netherlands, Belgium, and France. Within six weeks the German army had overrun the Low Countries and reached the English Channel. Paris had fallen, and France had asked for an armistice. The following year Germany turned its blitzkrieg tactics against the Soviet Union. It succeeded at first but eventually failed in the face of bad weather and stubborn Soviet resistance.

The United States Third Army under General George S. Patton, Jr., used similar tactics against the Germans in the summer of 1944, after Allied forces broke out of the Normandy beachhead in France.