Next day the center made a great blow against Gradisca and Sagrado, but the river line proved too strong. The only success was won that night at Plava, north of Borrigia, which was carried by a surprise attack. The Isonzo was in flood, and presented a serious obstacle to the onrush of the Italians. By June 14th the Italian eastern army had pushed forward along the gulf of Trieste toward the town of Nebrosina, nine miles from Trieste.
Meanwhile, the Austrian armies were being constantly strengthened. The initial weakness of the Austrian defensive was due to the fact that the armies normally assigned to the invaded region had been sent to defend the Austrian line in Galicia against the Russians. When Italy began her invasion the defenses of the country were chiefly in the hands of hastily mobilized youths below the military age of nineteen, and men above the military age of forty-two. From now on Austrian troops began to arrive from the Galician front, some of these representing the finest fighting material in the Austrian ranks. The chance of an easy victory was slipping from Italy's hands. The Italian advance was checked.
On the 15th of June the Italians carried an important position on Monte Nero, climbing the rocks by night and attacking by dawn. But this conquest did not help much. No guns of great caliber could be carried on the mountain, and Tolmino, which had been heavily fortified, and contained a garrison of some thirty thousand men, was entirely safe. The following week there were repeated counter-attacks at Plava and on Monte Nero, but the Italians held what they had won.
[Illustration: Map]
AREA OF GENERAL CADORNA'S SUCCESSFUL OPERATIONS AGAINST GORIZIA
The Isonzo valley forms the eastern line for the defense of Italy and
its possession was essential to the realization of Italian ideals.
Gorizia, its main strategic position, first fell to the Italians
August 9, 1916.
The position was now that Cadorna's left wing was in a strong position, but could not do much against Tolmino. His center was facing the great camp of Gorizia, while his right was on the edge of the Carso, and had advanced as far as Dueno, on the Monfalcone-Trieste Railroad. The army was in position to make an attack upon Gorizia. On the 2d of July an attack on a broad front was aimed directly at Gorizia. The left was to swing around against the defenses of Gorizia to the north; the center was directed against the Gorizia bridge head, and the right was to swing around to the northeast through the Doberdo plateau. If it succeeded the Trieste railway would be cut and Gorizia must fall.
Long and confused fighting followed. The center and the right of the Italian army slowly advanced their line, taking over one thousand prisoners. For days there was continuous bombardment and counter-bombardment. The fighting on the left was terrific. In the neighborhood of Plava the Italian forces found themselves opposed by Hungarian troops, unaccustomed to mountain warfare, who at first fell back. Austrian reserves came to their aid, and flung back three times the Italian charge.
Three new Italian brigades were brought up, and King Victor Emanuel himself came to encourage his troops. The final assault carried the heights. On the 22d of July the Italian right captured the crest of San Michele, which dominates the Doberdo plateau.
Meanwhile the Austrian armies were being heavily reinforced, and General Cadorna found himself unable to make progress. Much ground had been won but Gorizia was still unredeemed. Many important vantage points were in Italian hands, but it was difficult to advance. The result of the three months' campaign was a stalemate. In the high mountains to the north Italy's campaign was a war of defense. To undertake her offensive on the Isonzo it was necessary that she guard her flanks and rear. The Tyrolese battle-ground contained three distinct points where it was necessary to operate; the Trentino Salient, the passes of the Dolomites, and the passes of the Carnic Alps.
Early in June Italy had won control of the ridges of the mountains in the two latter points, but the problem in the Trentino was more difficult. It was necessary, because of the converging valleys, to push her front well inland. On the Carnic Alps the fighting consisted of unimportant skirmishes. The main struggle centered around the pass of Monte Croce Carnico.
In two weeks the Alpini had seized dominating positions to the west of the pass, but the Austrians clung to the farther slopes. A great deal of picturesque fighting went on, but not much progress was made. Further west in the Dolomite region there was more fighting. On the 30th of May Cartina had been captured, and the Italians moved north toward the Pusterthal Railway. Progress was slow, as the main routes to the railway were difficult.