On this day in 1917, the Italian army launches their 11th battle against Austro-Hungarian troops on the Isonzo River, near Italy’s border with Austria-Hungary.
With its mountainous terrain, the Italian front was the least well-suited of all the fronts of World War I for offensive warfare. Nonetheless, since 1915 the Italian army had launched no fewer than 10 attempts to overwhelm Austro-Hungarian forces, often with superior numbers, along the Isonzo, located in the eastern sector of the front in present-day Slovenia. After several quick initial successes by both sides, battle had settled into a stalemate, as it had on other fronts of the war. Desperate to make headway and please his more powerful allies, Italian Chief of Staff Luigi Cadorna continued to throw his men against the enemy at the Isonzo, where it was deemed essential to stop the Austrian advance over the mountains into Italy.
For this 11th attempt, Cadorna sent 51 divisions of men and 5,200 guns against the Austrian enemy. The Italian advance was impressive, pushing back the Austro-Hungarian line all along the front, with particular gains in the north by the Italian 2nd Army, led by Luigi Capello. In total, the Italians captured five mountain peaks and took over 20,000 Austrian (and some German) prisoners before the offensive ran out of steam and the Austro-Hungarian line eventually held their positions. The Italian attack was halted on September 12; they would make no further attempts on the Isonzo. The Twelfth Battle of the Isonzo—also known as the Battle of Caporetto—in late October 1917 marked a spectacular success for the Central Powers, and almost succeeded in forcing Italy out of the war altogether. With substantial Allied aid, and a new commander in chief, Armando Diaz, replacing Cadorna, Italy continued the fight. By the time World War I ended, in November 1918, half of the entire number of Italian casualties—300,000 out of 600,000—had been incurred along the Isonzo.