The twentieth century saw an unprecedented emphasis on fighting in all terrains seasons & weather conditions. Such conditions made even basic survival difficult as subzero temperatures caused weapons to jam engines to seize up & soldiers to suffer frostbite snow blindness & hypothermia. The conditions often favoured small groups of mobile lightly armed soldiers rather than the armoured forces or air power that dominated other combat environments. Some European armies developed small numbers of specialist alpine troops before & during World War I but these proved to be insufficient as nearly all the major combatants of World War II found themselves fighting for extended periods in extremely hostile cold-weather and/or alpine environments. Drawing upon manuals memoirs & unit histories & illustrated with period tactical diagrams & specially commissioned full-colour artwork this study sheds new light on the winter-warfare tactics & techniques of the US British German Soviet & Finnish armies of World War II.