The Italian plan of campaign apparently consisted first, in neutralizing the Trentino by capturing or covering the defenses and cutting the two lines of communication with Austria proper, the railway which ran south from Insbruck, and that which ran southwest from Vienna and joined the former at Fransensfets; and second, in a movement in force on the eastern frontier, with Trieste captured or covered on the right flank in the direction of the Austrian fortress at Klagenfurt and Vienna. The first blow was struck by Austria on the day that war was declared. On that day bombs were dropped on Venice, and five other Adriatic ports were shelled from air, and some from sea. The Italian armies invaded Austria on the east with great rapidity, and by May 27th a part of the Italian forces had moved across the Isonzo River to Monfalcone, sixteen miles northwest of Trieste. Another force penetrated further to the north in the Crown land of Gorizia, and Gradisca. Reports from Italy were that encounters with the enemy had thus far been merely outpost skirmishes, but had allowed Italy to occupy advantageous positions on Austrian territory By June 1st, the Italians had occupied the greater part of the west bank of the Isonzo, with little opposition. The left wing was beyond the Isonzo, at Caporetto, fighting among the boulders of Monte Nero, where the Austrian artillery had strong positions. Monfalcone was kept under constant bombardment. A general Italian advance took place on June 7th across the Isonzo River from Caporetto to the sea, a distance of about forty miles. Monfalcone was taken by the Italians on June the 10th, the first serious blow against Trieste, as Monfalcone was a railway junction, and its electrical works operated the light and power of Trieste. 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.