On October 24, 1917, a combined German and Austro-Hungarian force scores one of the most crushing victories of World War I, decimating the Italian line along the northern stretch of the Isonzo River in the Battle of Caporetto, also known as the Twelfth Battle of the Isonzo, or the Battle of Karfreit (to the Germans).
By the autumn of 1917, Italian Commander in Chief Luigi Cadorna’s strategy of successive offensives near the Isonzo River in northern Italy—11 Italian attacks since May 1915 preceded the Austrian assault at Caporetto—had cost the Italians heavy casualties for an advance of less than seven miles, only one third of the way towards their preliminary objective, the city of Trieste on the Adriatic Sea. Despite this, the wave of Italian attacks had also taken a serious toll on Austro-Hungarian resources in the region. Indeed, in the wake of the Eleventh Battle of the Isonzo in August 1917, Austria’s positions around the city of Gorizia were dangerously close to collapse. As a result, the German Supreme Command, led by Paul von Hindenburg and Erich Ludendorff, determined with their Austrian counterpart, Arz von Straussenberg, to launch a combined operation against the Italians, intended for mid-September.
In preparation for the offensive, Germany transported seven divisions of troops to reinforce the Austrians on the upper banks of the Isonzo. Cadorna, learning by aerial reconnaissance of the Austro-German movements, pushed back his own army’s scheduled September offensive to prepare a defensive position for the scheduled attacks that month. Unfavorable weather, however, pushed back the plans, and by the time Germany and Austria-Hungary were ready to attack, they were able to catch the Italians by surprise. On October 24, after a brief, effective artillery bombardment, the German and Austrian infantry moved ahead against the damaged Italian lines, using grenades and flamethrowers to exploit their advantage and achieve a quick and decisive breakthrough. By the end of the day, they had advanced an impressive 25 kilometers.
Though the Italians managed to harden their defensives over the coming weeks, by mid-November the Germans and Austrians had driven them back some 60 miles to the River Piave, just 30 kilometers north of Venice. Italian casualties at Caporetto totaled almost 700,000—40,000 killed or wounded, 280,000 captured by the enemy and another 350,000 deserted. In the wake of the battle, violent anti-war protests reached a peak in Italy, as Cadorna was forced to resign his command. His successor, General Armando Diaz, would oversee a new Italian strategy—defensive, as opposed to offensive—for the remainder of the war, including a greater reliance on the resources of the stronger Allied powers.