During its darkest hour Switzerland was surrounded by aggressive fascist armies, with no allies within reach, its politicians quavering, and its people beginning to lose hope of retaining their freedom. General Henri Guisan stepped into this miasma of growing despair. In July 1940, he assembled the entire Swiss officer corps at the Rutli Meadow, the spot where pike-wielding herdsmen had formed the Swiss Confederation in 1291. Invoking the spirit of their medieval forebears, he informed his officers that Switzerland would fight back against any invader, and if they ran out of ammunition they would use the bayonet. Switzerland, he declared, would never surrender. Guisan lit a torch that would guide the Continent's only remaining democracy until the end of the war. The key to his military strategy was shifting the main strength of the Swiss Army to the Alps. This controversial policy conceded population centers but it also negated German superiority in armor and aircraft. If the Nazis invaded they would only open a bleeding sore that they would not be able to close. Though the Wehrmacht drew up numerous invasion plans, it never took the gamble. As a military man who became the spiritual leader of his country, Guisan was a rarity in the history of democratic nations. His guidance, along with the Swiss system of universal male conscription, meant that the Germans, had they invaded, would have been fighting not just an army but a people. This definitive biography of General Guisan not only describes a man of great complexity and courage, but a fascinating aspect of World War II. WILLI GAUTSCHI is the author of numerous works, including "The National Strike of 1918" and "Lenin as an Emigrant in Switzerland." Having retired from teaching history at the University of Zurich, he currently lives in Baden.