Italy entered the Great War on the side of the Entente, with the goal of gaining the Trentino and Trieste areas from Austria-Hungary. The existence of fixed defenses on both sides dictated that from the outset the campaign would be mainly static. In murderous fighting, the Italians managed briefly to capture key tactical positions on the Isonzo Front, like Monte San Michele overlooking Gorizia, only to be thrown off them again by determined Austrian counterattacks. Eventually December brought mutual exhaustion, and the fighting petered out as both sides tried to cope with the freezing cold of winter in the mountains.
Before the war, Italy was allied with the Central Powers. On the outbreak of war in August 1914, the Italians reneged their commitments, claiming that the aggressive nature of the actions taken by the Central Powers breached the defensive nature of the original treaty agreements. An alliance containing Austria-Hungary was never likely to sit well with an Italian population, who still harbored a grudge against the Austrians over disputed territories, particularly focussed on the Trentino and Trieste areas.
Once it became evident that Italy was not entering the war on the German side, there was a rush by British and French diplomats to secure the Italians to augment the ranks of the Entente. These efforts culminated in the secret Treaty of London under the provisions of which Italy would declare war on the Central Powers in return for promises of gains in the disputed provinces in the Tyrol and the Austrian Littoral which included the port of Trieste. Agreements were also hammered out over the division of the spoils with Serbia along the Dalmatian coastline of the Adriatic. In consequence, Italy declared war on Austria-Hungary.
The Italian Army was large, consisting of some 850,000 soldiers, and based on a conscription system, but there were severe problems with both equipment and training. The officers were still recruited from a fairly narrow regional base and there was an inherent lack of professionalism in their general approach. Although King Victor Emmanuel III was nominally Commander-in-Chief, the Italian Chief of General Staff and de facto commander was General Luigi Cadorna.
The Austro-Hungarian Army was already under relentless pressure in 1915. The addition of the Italians to its roster of enemies, which included the Russians and the Serbs, did not bode well. Yet in another sense the Italian timing was dreadful as it coincided with the advent of a massively increased level of support from Germany for the ailing Austria-Hungary on the Eastern Front. This would greatly ease the situation for the Austrians and allow them to reinforce the Italian Front in a manner which otherwise would have been impossible.
Shortly after the declaration of war, the Italians began their advance across the border, pushing forward to the Isonzo, while the Austrians fell back across the flood plain to the higher ground east of the river. At first the Italians made some useful gains, including the town of Caporetto in the north, and some progress in the Julian Alps east of the Isonzo, but ultimately their offensive ground to a halt.
The First Battle of the Isonzo followed shortly afterwards, with frontal attacks on the Austrian bridgehead opposite Gorizia and on the Carso Plateau. But these merely confirmed that any further advances would be extraordinarily difficult. Even where the Italians made small gains they were promptly hurled back by Austrian counterattacks.
In the Second Battle of the Isonzo, the story was essentially the same as the Italians charged forward time and time again – a story retold as tragedy. Although he had scraped together every possible gun from forts and naval sources, Cadorna still had nothing like enough guns or shells, or indeed gunners with the skills to accurately target Austrian strong points. The Second Battle was the first full-scale bloodbath on the front, costing 42,000 Italian casualties.
During the third attack on the Isonzo front, the Italians were able to advance at Plava, near the Isonzo Canal and at Mount Saint Michele, in an attempt to outflank the Austrians defending Gorizia. In the end, however, the Austrians were able to hold their positions. Both sides suffered terrible casualties. The last days of the battle were extremely violent. Brigade diaries reported fears that some units might crack and desert en masse. The attacks on San Michele were weakening under the internal pressures of exhaustion and hopelessness. The Italians had sustained 67,000 losses along the front.
During the Fourth Battle of the Isonzo the Italians were able to make small gains, capturing the hills overlooking Gorizia. On the other sectors of the front the Italians were not able to make any gains, despite brutal fighting and numerous casualties.
In their first four Isonzo attacks alone the Italians lost 161,000 men and the Austrians nearly 147,000 killed, wounded, captured and missing. More Italians were called from the reserve to the colors. As winter descended, the tempo of operations slowed, and cholera, supposedly contracted from the Austrians, spread through the Italian army.