Italian Forces, 750,000
General Luigi Cadorna, Commander-in-Chief
Duke of Aosta
Austrian Forces, 750,000
General von Hofer
General von Rohr
At midnight on May 23, 1915, the Armies of Italy were set in motion northward to seize and close the gateways of the Austro-Italian frontier, which extended 450 miles from the Swiss border to the Adriatic Sea, a stretch half again as long as that covered by the Allied front in Belgium and France. Throughout its greater part, this frontier was formed by the natural barrier of the Alps, whose myriad peaks tower miles in air, overlooking the sunny plains of Venice and Lombardy. Along this mountain barrier the Austrians had constructed a system of defensive works, which seemingly defied frontal attacks.
From foothills to summits, these awesome Alpine slopes were seamed with parallel lines of trenches, protected by wire entanglements and with permanent gun emplacements and turrets fixed at intervals. To assault this mountain fortress in mass was deemed impracticable; only by attacking each fortified peak in separate operations and by relatively small bodies of troops might success be attained. Yet it was necessary to cover the whole extent of the frontier with Italian troops, lest the Austrians should pour down into the Northern plains of Italy. The actual goal of the Italian Armies, however, was not the Trentino and Tyrolean regions in the North, but Trieste in the East.
The way to Trieste, through a 25-mile passage along the Isonzo River, between Cividale and the Adriatic Sea, was unopposed by the Alps. Instead, two parallel railways, some ten miles apart, led eastward from the Isonzo front, one from Gorizia following the course of a branch of the Isonzo River; the other from Monfalcone by way of Carso, following the seacoast direct to Trieste. The central pivot of the...