The Carpathian campaign of 1915, described by some as the "Stalingrad of the First World War," engaged the million-man armies of Austria-Hungary and Russia in fierce winter combat that drove them to the brink of annihilation. Habsburg forces fought to rescue 130,000 Austro-Hungarian soldiers trapped by Russian troops in Fortress Przemysl, but the campaign was waged under such adverse circumstances that it produced six times as many casualties as the number besieged. It remains one of the least understood and most devastating chapters of the war-a horrific episode only glimpsed previously but...