The Coasts of Italy and Austria, Showing the Naval Raid May, 1915.
The Austrian fleet began its attack early on the morning of Monday, May 24, 1915. The ships engaged were a squadron from Pola, consisting of two battleships, four cruisers, and eighteen destroyers, strongly supported by aircraft. The assault extended from Brindisi to Venice, and covered a large extent of coast territory hard to defend. At Venice the Austrian air raiders dropped bombs into the arsenal and the oil tanks and balloon sheds on the Lido. The priceless relics of art and architecture, all that remained to recall the city's proud position as ruler of the Adriatic, were uninjured, but the attack from the air caused an outcry from the nations of the Entente almost equal to that which rang through the world when the Germans shelled the cathedral at Rheims and destroyed Louvain. The Austrians replied that the attack was a serious military operation, and by no means the wanton outrage their enemies had tried to make it appear.
The Austrian naval raid lasted barely two hours, but in that time the cruiser Novara and several destroyers attacked Porto Corsini, north of Ravenna, in a vain effort to destroy the Italian torpedo base; the cruiser St. Georg shelled the railway station and bridges at Rimini; the battleship Zrinyi attacked Sinigaglia, and wrecked the railway station and bridge; south of Ancona the battleship Radetzky destroyed a bridge over the River Potenza. In the south the cruisers Helgoland and Admiral Spaun with destroyers shelled a railway bridge and station and several signal stations in the neighborhood of Manfredonia and Viesti, and caused some damage in small coast towns. The raid was well planned and swiftly executed, and it accomplished much of its purpose. The Italian fleet was taken by surprise, and the marauders were back in safety at Pola by six o'clock in the morning, unharmed.
While Italian Alpine troops were driving in the Austrian outposts on the frontiers of Trentino and the Tyrol, General Cadorna advanced his main infantry force, the Third Army, across the Friuli Plain through Udine, Palmanova, and St. Georgio toward the Isonzo. Here the covering troops on May 24 and 25 had captured nearly all the small towns and villages between the frontier and the river from Caporetto in the north just below Monte Nero to Belvedere in the south on the Gulf of Trieste. Cadorna feared lest his opponent, General von Hofer, would launch his main attack from Gorizia against the Italian city of Palmanova, fourteen miles to the west. But Von Hofer, so it developed, had a subtler plan of campaign than a direct attack through Gorizia. What he did was to place a strong force on the mountain of Korada between the Isonzo and the Judrio. This height commanded the middle course of the Isonzo, and it had been transformed into a network of permanent trenches, protected by strong wire entanglements.
The Austrian general believed that by the time the Italians could bring up their heavy artillery and begin to smash the entanglements with their field guns, supports could be pushed across the river. Realizing that Korada must be captured, if at all, by dash and surprise, the Italian brigadier in charge of the attack gathered a herd of fierce bulls, which are numerous in that part of Venetia, and penned them in a hollow out of sight of the enemy, while his artillery began to bombard the hostile trenches. When the animals were wrought to a frenzy of rage and fear by the noise of the guns, they were let loose and driven up the mountain against the Austrian positions. Their charge broke through many strands of the wire entanglements, and before the last of them fell dead under the Austrian rifle fire, Italian troops with fixed bayonets had crowded through the gaps in the wires and captured the position.
By the end of May, 1915, the Third Army had reached the Isonzo River, but had not crossed. Its advance was slow and cautious. Operations were hampered by the heavy rains, which caused the river to overflow its banks and added greatly to the difficulties put in the path of the advancing army by the Austrians, who, as they withdrew, left not a bridge behind them.
Grado, a fishing town of about 5,000 inhabitants, but important on account of its strategic situation, was occupied by the Italians with no great difficulty. Grado lies at the head of the Adriatic, and is twelve miles from Trieste and sixty from Pola. The waters of the lagoons in this neighborhood were valuable to the Italians as a safe shelter for submarines and other small war-craft, and as a base for a prospective attack later upon Pola itself. The inhabitants, most of whom preserved their Italian traits and sympathies, although the town had been under Austrian rule since 1809, hailed the conquerors enthusiastically. Cannon and military carriages were decorated with flowers. Thousands of Italian flags appeared as if by magic. The entering troops were greeted with shouts of "All our lives we have been waiting for this moment when we can cry 'Viva Italia!'" The possession of Grado gave the Third Army virtual control of the mouth of the Isonzo, but the main Austrian position of defense at Gorizia remained apparently unweakened.
Scenes like those at Grado were witnessed at Ala, the first Austrian town of any size and the first railroad center captured by the Italians in the Trentino. Ala was occupied May 27, 1915. Three days before this the Italian light infantry had massed behind the boundary line, and when they began their advance along the main highway their first act was to pull down the yellow and black pole that marked the frontier.