It will be recalled that their successes in 1916, which gained for them Goritz, had left them still without possession of the heights, rising from 1,800 to 2,200 feet to the northeast and east of that town and had brought them to the edge of the mountains to the west of the Carso Plateau. In a twenty-five days' campaign, begun May 14, 1917, they had then improved this position by crossing the Isonzo to the north of Goritz, by capturing Monte Cucco on its east bank and by extending their positions along this bank so as to include the Vodice Ridge, bringing them right up against the slopes of Monte Santo. On the Carso, too, they had succeeded in advancing so that their artillery could reach the heights west of it, including the Hermada Hills. Their line then, as constituted in August, 1917, began some miles southwest of Tolmino, ran for a little more than five miles along the west bank of the Isonzo, crossed it west of the village of Decla, ran along the east bank for about five more miles, then opposite a bend in the river turned south for about another five miles to the San Marco, running at a distance of about one and one-half miles east of Goritz, and then twisted in a general southern direction for some fifteen miles, crossing in its course the valley of the Vippacco River, down to the Gulf of Trieste where it ended about two miles southeast of Monfalcone. It appears that in the new drive, now started, there were engaged: The Third Army, under General Cappello, in the north, on the Bainsizza Plateau, Monte Santo, Monte San Gabriele, and the approaches to San Daniele; the Second Army, under the Duke of Aosta, operating south to the sea, in the valleys of Vippacco and Brestovizza, on the Carso, and before Hermada; British and Italian monitors, which bombarded Hermada and the Austrian ships and arsenals at Trieste and Pola; the great Caproni aerial machines, which both on the battle line and over Trieste and Pola aided the work of the soldiers and warships. Not until August 19, 1917, did it become known that for many weeks prior to the beginning of the offensive the Italians at sundown every night had by a great engineering feat diverted the water of the Isonzo above Anhovo, and had built in the shallow stream thus left 10-foot bridges, which were concealed from view when the water resumed its natural course each morning. On the eve of the crossing they supplemented these with four pontoon bridges laid while their searchlights blinded the eyes of the Austrians on the opposite cliffs. These bridges extended from Anhovo up to Loga, a distance of four miles. That night, August 18, 1917, the stream remained diverted and the army of Cappello crossed, while the Duke of Aosta performed a diversion on the Carso.