Italian and Austro-Hungarian troops clashed at altitudes up to 12,000 feet (3,600 meters) with temperatures as low as -22°F (-30°C) in the Guerra Bianca, or White War, named for its wintry theater. Never before had battles been waged on such towering peaks or in such frigid conditions.

Now, a century later, the warming world is revealing the buried past, as relics and corpses are melting free of their icy tombs.

Italy began the war on May 23, 1915. Its aim, stoked by a rising nationalist fervor, was to annex several regions—particularly those inhabited by Italians—held by the Austro-Hungarian Empire.

Troops fought and died all along the frontier, from Trentino to the Adriatic, for the next three years. Perhaps most remarkable, though, was the White War, a series of impossible—and ultimately futile—blitzes, incursions, athletic feats, and engineering coups.