Italy’s reason for declaring war was to gain territory, so its armies went on the offensive from the start. The year 1915 was dominated for the Italians by their attempts to break through the Austro-Hungarian line on the Isonzo river, but there were also naval encounters and bombing raids across the Adriatic Sea. The Austro-Hungarians defended effectively throughout 1915 as whenever they lost territory they were ordered to immediately recapture it at all costs.
Italy entered The First World War on May 23, 1915, declaring war only on Austria-Hungary, from which it hoped to gain territory promised by the Treaty of London negotiated with the Allies on April 26 in return for giving up neutrality to join them. However, for geographical reasons this was a particularly ambitious goal. The 400 mile long border between Austria and Italy passed through high mountains, which naturally gave the defenders an advantage. There were only two possible areas where the Austro-Hungarian defences could possibly be broken; through the passes to the Trentino to the north, or via the valley of the Isonzo River in the Julian Alps to the east. The Trentino route would have to be ruled out because the passes were already in Austrian hands and heavily fortified. The main Italian effort throughout the war was therefore launched across the Isonzo towards Slovenia, Trieste and Istria. This presented huge problems for troop concentration and mobility. Furthermore the Italian supply lines were always vulnerable to attack from the Trentino , so some forces always had to be diverted in that direction to cover the main force. It also required clearing the vast windswept Bainsizza Plateau to the east, a series of desolate, rocky ridges.
The Italian Front 1915 -1917
The Central powers were aware of Italy’s negotiations and secret deal with their enemies, and by the time war was declared the Austrians were ready for them. With only seven divisions in all, they were heavily outnumbered, but were superior in artillery and machine-guns. In initial skirmishes in June, Italian Alpine troops climbed the 2,300 m Monte Nero overnight and swept the few defenders from the summit. This early success created unrealistic expectations. The main advance began on June 23 with an artillery barrage that destroyed the monastery of Sveta Gora, a Slovene national treasure, but not many of the Austro-Hungarian defence posts. Commander-in-chief Cadorna aimed to take Gorizia and the bleak Carso plataeu, gateway to the Trieste. Casualties in the first of the many battles of the Isonzo were heavy with over 30,000 Italians and 20,000 Austrians killed or wounded in action. A shortage of front-line doctors meant that many Italian wounded were left unattended, and transport problems caused severe shortages of food and water. Some Italian officers even forced their men forward at gunpoint, and both sides threw rocks when the ammunition ran out. On July 7, with Italian advances being minimal, Cadorna called a halt to the offensive. He dismissed 27 Generals and blamed the failure on everyone but himself.
Italian Alpini Troops
The second battle of the Isonzo began on July 18, the main objective being Monte San Michele on the edge of the Carso. This time the artillery barrage was heavier and more effective. Every shell bursting on the limestone terrain discharged a hail of rock fragments more deadly than bullets to soldiers without helmets. The Italians gained the summit, but were driven off next day in a counter attack spearheaded by knife-wielding Bosnians. The Italians retook it on July 25, and were again pushed off. The tactics of the Austrian commander Boroevic were simple: if a position was lost, recapture it immediately.
Fighting on Carso gradually died away with Trieste still over 20 miles distant. A fruitless assault on the Upper Isonzo continued, but heroism was unavailing against well entrenched machine-guns. Cadorna was still convinced he could break through, but he needed two months for recovery and reinforcements. The third battle of the Isonzo began on October 18 with a three-day artillery barrage. Gorizia was now Cadorna’s objective. The Italians reached its suburbs but could not take the town, and the offensive ended at the beginning of November. The Fourth Battle began a week later and lasted into December. Italian gains remained insignificant and one regiment mutinied. Battles at the Isonzo continued into late 1917 accounting for half of the entire Italian war casualty total.