This up to 2.5-kilometre-wide territory entered the history as the Tolmin bridgehead. In such a way Austria-Hungary defended the important railway- and road connections with the inland of the monarchy. The hills Mengore, Bučenica and Cvetje formed a blockade on the right bank of the Soča. Mrzli vrh from where it descended to the Tolmin basin. Rombon to the Bovec basin, along the valley of the Slatenik to the Krn range and across Mt. The front line between the Italian and the Austro-Hungarian armies ran from the top of Mt. Civilians from the settlements in the immediate vicinity of the front were evacuated and forced to seek refuge the settlements were occupied by soldiers. The fights took place mainly in the mountainous world. The Twelfth Isonzo Battle (24 October–9 November 1917)Īfter the initial shifting, the front line in the Upper Soča Region stabilized and turned to a static warfare. The Eleventh Isonzo Battle (17 August–12 September 1917) The Tenth Isonzo Battle (12 May–5 June 1917) The Ninth Isonzo Battle (31 October–4 November 1916) The Eighth Isonzo Battle (9–12 October 1916) The Seventh Isonzo Battle (13–17 September 1916) The Sixth Isonzo Battle (4–16 August 1916) The Fifth Isonzo Battle (11–16 March 1916) The Fourth Isonzo Battle (10 November–2 December 1915) The Third Isonzo Battle (18 October–4 November 1915) The Second Isonzo Battle (18 July–3 August 1915) The First Isonzo Battle (23 June–7 July 1915) Eleven of them were launched by the Italians, the last one, the twelfth, by the soldiers of Austria-Hungary and Germany. During the twenty-nine months of warfare, May 1915 through October 1917, several fierce combats and twelve offensives took place in this area. Rombon to the Adriatic was named the Isonzo Front. The ninety-kilometre-long section of the front that ran along the Soča (Isonzo) River from Mt. Thus, the south-west front was opened it was more than six hundred kilometres long, running from the Pass of Stelvio on the Swiss-Italian-Austrian border trijunction, across the mountain region between Trentino and Veneto (at that time Trentino was part of the Austro-Hungarian Empire), the Carnian Alps, and through the Soča Region to the Adriatic. Signing the Treaty of London, negotiated between Italy and the Triple Entente, Italy quit the alliance and declared war on Austria-Hungary on , starting the operation the next day, on 24 May. During the first year of the war, in spite of its partnership in the trilateral alliance with Austria-Hungary and Germany, Italy remained neutral. Europe turned to a vast battlefield, divided into several fronts, since two opposing “blocks” entered the war: the Central Powers (Germany, Austria-Hungary, Bulgaria and Turkey) on the one side and the Triple Entente (France, Great Britain and Russia) on the other.
In the first days of August, several countries exchanged the declaration of war, which meant the outbreak of World War I. After the Austro-Hungarian ultimatum to the Kingdom of Serbia, Austria-Hungary declared war on Serbia a month later (on 28 July 1914).
Future Italian offensives were aimed at Fajti Hill (Monte Faiti), Trstelj and Grmada.On 28 June 1914, Archduke Franz Ferdinand of Austria, heir presumptive to the Austro-Hungarian throne, and his wife Sophie were assassinated while on a visit to Sarajevo. The planning of future Italian offensives was based on the fact that they occupied Gorizia, the demand of Italian politicians to acquire Trieste at any cost and the realisation of the Italian high command that the sixth offensive had been prematurely halted, since the Austro-Hungarian side had not managed to fortify a third and fourth lines of defence. In the second phase of the offensive, the defenders managed to stop the Italians from breaking through to the Banjščica Plain and thus from entering the Vipava Valley and surrounding their units in the Karst. They held most of their positions in the central and upper Isonzo Valley. The Austrians held the defensive positions on the left bank of Soča (Isonzo) River while the trenches there had barely been dug. On 9 August, their units entered Gorizia and forced the units defending the Karst, especially the Doberdob plain, to retreat. The Italians planned to occupy Goricia and the Doberdob plain. The Sixth Battle of Isonzo (4 August–16 August 1916).