Originally the fierce storms that twice saved Japan from Mongol invasion (in 1274 and 1281). In World War II a kamikaze was an aircraft laden with explosives and suicidally crashed by the pilot into an enemy ship. The Japanese naval command resorted to these desperate measures in 1944 in an attempt to halt the Allied advance across the Pacific. At first volunteers were used, but the practice soon became compulsory. Off Okinawa in 1945 over 300 kamikaze pilots died in one action.