While the modern tank dominates land warfare, the idea of armor goes back to ancient times as the Greeks, Assyrians and Romans all had hardened material for their soldiers. By the 5th century chain mail become used for a 1,000 years until mobility became more important than heavy armor in the 16th century. In World War I armored fighting vehicles appeared on the battlefield to counteract the dominance of the machine gun. Eventually the tank became the dominate piece. The first U.S. tanks were used in combat on September 12, 1918 with the force commanded by then Lieutenant Colonel George Patton, the first officer assigned to the U.S. Tank Corps. In World War II German General Heinz Guderian created the first modern armored force and revolutionized the battlefield ushering the Blitzkrieg - Lightning War. The Battle of Kursk in WW II saw the largest tank battle ever with over 1,500 German and Russian tanks fighting at point blank range. General Patton's Third Army during World War II became the prototype of the U.S. combined arms force that is still essentially the same concept today.