The Great War toppled four empires, cost the world 24 million dead, and sowed some of the seeds of another worldwide conflagration 20 years later. Yet, until now, there has been no comprehensive treatment of how Germany and Austria-Hungary - two of the key belligerents - conducted the war and what defeat meant to them. How did the Hohenzollern and Habsburg empires conceive of and conduct 'total war'? What impact did the prolonged fighting have on their societies? Drawing on his own archival research over the past decade, Holger Herwig analyses why Vienna opted for war in 1914 and why Berlin took the calculated risk to back that decision. The war plans and military campaigns on both Eastern and Western fronts are examined in detail and key battles, some of the bloodiest and most wasteful in military history, are narrated and analysed. On the home front, the mobilization of the civilian populations behind the war effort had profound social consequences. The militarization of the key war-related industries led to an industrial women's labour force emerging in both countries, deeply affecting the role of women in Germanic society. ''The great seminal catastrophe of the twentieth century', as American statesman George F Kennan described the war, has had no shortage of accounts seen chiefly from Allied perspectives. In using Vienna and Berlin as his vantage points, Herwig has comprehensively shown for the first time the other side of that prodigiously wasteful conflict.