Along with the Zen military training, the Japanese placed the entire country on a wartime footing, with every able-bodied man engaged in constructing shoreline fortifications. As expected, in the early summer of 1281 the Khan launched an invasion force thought to have numbered well over 100,000 men, using vessels constructed by Korean labor. When they began landing in southern Kyushu, the _samurai_ were there and ready, delighted at the prospect of putting to use on a common adversary the military skills they had evolved over the decades through slaughtering one another. They harassed the Mongol fleet from small vessels, while on shore they faced the invaders man for man, never allowing their line to break. For seven weeks they stood firm, and then it was August, the typhoon month. One evening, the skies darkened ominously in the south and the winds began to rise, but before the fleet could withdraw the typhoon struck. In two days the armada of Kublai Khan was obliterated, leaving hapless onshore advance parties to be cut to ribbons by the _samurai_. Thus did the Zen warriors defeat one of the largest naval expeditions in world history, and in commemoration the grateful emperor named the typhoon the Divine Wind, Kamikaze. The symbols of the Zen _samurai _were the sword and the bow. The sword in particular was identified with the noblest impulses of the individual, a role strengthened by its historic place as one of the emblems of the divinity of the emperor, reaching back into pre-Buddhist centuries. A _samurai's _sword was believed to possess a spirit of its own, and when he experienced disappointment in battle he might go to a shrine to pray for the spirit's return. Not surprisingly, the swordsmith was an almost priestly figure who, after ritual purification, went about his task clad in white robes. The ritual surrounding swordmaking had a practical as well as a spiritual purpose; it enabled the early Japanese to preserve the highly complex formulas required to forge special steel. Their formulas were carefully guarded, and justifiably so: not until the past century did the West produce comparable metal. Indeed, the metal in medieval Japanese swords has been favorably compared with the finest modern armorplate.