In the winter between 1916 and 1917 and at the beginning of the spring, the war operations were characterized by a standstill. With the good season the Entente Forces restarted the initiative. In May 1917, while the great spring offensive was underway on the west, between Soissons and Craonne, the Italian Superior Command decided to support it indirectly by attacking along all the front of the Isonzo. The action was performed from 12^th to 28^th May determining the 10^th battle of the Isonzo.

The two Corps of the 2^nd Army attacked Kuk, Vodice and Monte Santo. The battle protracted until the 22^nd and ended with the occupation of the first two mounts and the slopes of the third. After having attracted the Austrian reserves, the 3^rd Army started a violent attack on 23^rd, from Castagnevizza to the sea. It managed to reach the Flondar line but on 28^th the operation ended.

Then, from 10^th to 29^th June, the Italian Army carried out an assault in the Uplands sector (the battle of Ortigara) that ended without any positive result and with a lot of losses. This battle aimed to improve the situation along the Trentino front, in view of the deep overhang on Bainsizza because “going further from the vicentina plain over the Isonzo meant increasing the danger of the trentino salient”, as Cadorna wrote.

A great number of critics blamed General Cadorna for the lack of important results in this offensive as well as in others. But these battles were part of a strategic vision agreed with the Allies, that was based on the attrition the enemy through offensive operations. Soon after, in order to improve the positions on the left of the Isonzo, the Italian Superior Command decided to carry out an offensive action (11^th battle of the Isonzo) that would have led up to the occupation of the upland of Bainsizza, up to Vallone of Chiapovano, as well as to the conquest of the upland of Comen over the Hermada. The offensive, simultaneous in the two areas, lasted from 17^th to 31^st August and led up to some results.

The 2^nd Army crossed the Isonzo and, after bloody attacks that lasted ten days, it managed to enter the upland of Bainsizza for 8 km without driving away the enemy definitely.

Instead the 3^rd Army got only modest results, moving ahead the front near Hermada. This was the last offensive battle of the Italian Army on the front of Isonzo.

The Italian losses were terrible: 40 000 deaths, 108 000 wounded and 18 500 missing people. The Italian Army was wearing out and in the fighting departments the hope to reach the rock barrier in front of them faded.
Austria-Hungary started to feel the effects of the defeats. It was sure it could not carry out other offensives in those conditions with the same power and intensity.

On 25^th August 1917, when the 11^th battle of the Isonzo was still underway, the Austrian Command decided to ask for a German help, designating General Waldstätten to present officially the request to the German Command. This was an humiliation for the young Emperor Carlo but he was aware that his Army could not resist to another attack! The German forces intervened supporting the Austrian forces on the Giulio front. The French inactivity, after the defeat of the offensive Nivelle and the collapse of the Russian army, led up to a temporary supply of German reserves to be employed in favour of Austria against Italy, in order to forced it to surrender.
Seven German divisions arrived in Italy and, along with 8 Austrian divisions, they constituted the 14^th Army, headed by the German General Otto von Below. The Italian offensives caused the outbreak of that violent attack!
When General Cadorna was informed with a little precision about the Austro-German preparation, he renounced to carry out some offensive operations to improve the situation in the front; on 18^th September General Cadorna ordered the 2^nd and the 3^rd Army to take on a defensive attitude. The Duke of Aosta, who was the 3^rd Amy Commander, conformed to the orders while General Capello, the 2^nd Army Commander, thought that his troops had to maintain an offensive formation because it would be easier for them passing to the counteroffensive.
Cadorna, who was sceptical​ about the Austrian effort, did not control the actualization of his orders and, as a consequence, the 2^nd Army had​ an inappropriate formation when the enemy carried out its offensive.

The Austro-German attack started on ​​24^th October at 2.00 a.m., through a violent preparation of the artillery. At the dawn, the 12^th German division (arrived from Tolmino), broke the Italian line and it passed through the valley of the Isonzo to reach Caporetto at 3.00 p.m.
Moreover, the German Alpine Corps​ conquered in a day all the eastern region of Kolovrat, stronghold of the Italian backward defensive line. The movement of the first two German units was immediately followed by other 5 divisions. In the evening of 24^th October the right side of the 1^st and the 2^nd defensive line (from Tolmino to Kolovrat) had already outflanked and the centre of the 3^rd line in Caporetto was passed. The day after the Austro-Germans carried out a manoeuvre crossing overpassing the Isonzo, in Saga, reaching Monte Maggiore. To the north, the 10^th Austrian Army went to Tagliamento; to the centre, the troops with the 12^th German division from Caporetto reached the lateral pick of Matajùr; the left side of the enemy assault formation aspired to the roads of Cormons and Cividale from Kolovrat.

On 26^th, after having passed almost all the mountain defensive positions, the 14^th Army arrived to the plain and aspired to Cividale while the 10^th Amy to the north reached the valley of Fella. The group of the Boroevic Armies started the offensive on the Carso. At 2.00 of the 27^th October, the Italian Superior Command ordered the general retreat. The Tagliamento line became the first line of the resistance; but then they considered the retreat  up to the Piave as a necessity. The 4^th Army and the Corps of Carnia went to that line, following the high valley of the Piave. Strong rear guards and cavalry divisions protected the movement of the last part of the 2^nd Army and the entire 3^rd Army that ran the risk to be outflanked by the enemy on Tagliamento. On the same line a first defence​ was organized and it resisted from 31^st October to 4^th November. On 9^th November, all surviving troops had already reached the right bank of the Piave river where a part of the Italian Army was deployed to face the invader. The Austrian Command decided to continue the offensive until the destruction of the Italian Army. The final battle developed into two phases: from 10^th to 26^th November and from 4^th to 30^th December. In the first phase the Austro-Hungarians attacked along the Piave and on 12^th November they managed to enter the bay of Zenson without the possibility to move forward. On 16^th November they crossed the river in Fagaré but they were counterattacked and they had to go back. In the low Piave, they forced the defensive line to move back to the south of Musile, along the Old Piave, the Sile, in Cavazuccherina and Cortellazzo. In spite of this local success, the offensive along the Piave failed and it was not renewed. The battle on the upland of Sette Comuni and on Grappa (since 12^th November) was violent. On the Upland an extreme attempt to break, that was done on 22^nd​ November at the presence of the Emperor Carlo, was repelled. On Grappa the Austro-Hungarian divisions and the German ones of the 14^th Army performed violent attacks for several days: they only managed to take some advanced positions and on 26^th November the Austro-Hungarian Superior Command ordered the suspension of the offensive.

Meanwhile some divisions were reorganized and the Italian Superior Command could substitute a lot of troops that were in line during the tragic days of the desperate defence. Between 4^th and 5^th December some French and English divisions entered in line between M.Tomba and Montello, in an area where the Austro-Hungarians did not carry out attacks. On 14^th​ December the 11^th Austro-Hungarian Army started the second phase by attacking, with 43 battalions and 500 cannons, the Melette defended by the 29^th Italian Division with 21 battalions and 160 cannons; it managed to take possession of the area, forcing the defence to inflect the line in Col d’Echele, Col del Rosso and Monte Valbella. On 11^th December the 14^th Austro-Hungarian Army restarted the offensive on Grappa: through a hard struggle, the Army could occupy Col della Berretta, Col Caprile, Monte Asolone, Monte Spinoncia, but it could not take advantage of these limited successes. The last attack was launched on 19^th December but it found the Italian defences impassable for the warriors' virtue. The last offensive was on the Upland where the “Christmas battle” took place. On 25^th December the 3^rd​ Austro-Hungarian Corps attacked, with 33 battalions and 560 cannons, the 22^nd Italian Corps that had 24 battalions and 200 cannons. It managed to take possession of M.Valbella and Col d’Echele, but the defence​ strengthened on the rear line Cima Echar-Monte Melago-Pizzo Razea.

The hard battle ended with the confessed displeasure of the Austro-Germans and their first failures: on 30​​^th Dec​​ember the 47^th French Division reconquered the ridge between M.Tomba and Monfenera and on 31^st the Austro-Hungarian troops in the Zenson bay had to cross again the Piave because of the presence of the Italian infantry. The battle of Caporetto represented for the Italian Army an agonizing failure that affected all the Nation. The sudden loss of Friuli, Carnia, Cadore (Italian territories and densely populated), of 300 000 men and 3 000 pieces of artillery as well as all the stocks with military materials between Isonzo and Piave, it represented a terrible blow. Two aspects need to be clear:

• only the geographical trend of the borderline changed the tactical failure into a strategic defeat;
• Caporetto represented for the Italian Army an unlucky event to which it could remedy by itself very soon.
  

The retreat along the Piave was headed by General Cadorna (succeeded by General Diaz on 9^th November, day in which the retreat ended); it was an Italian event such as the following victorious final battle. After the final battle, while the Country supported the Superior Command in the total reorganization of the military instrument, the Italian Army did not remain inactive. Since the line of the resistance at the eastern far end of the upland of Sette Comuni was unstable after the “Christmas battle”, an offensive was organized from 28^th​ to 30^th January and it ended victoriously with the reconquest of the M.Valbetta-Col del Rosso-Pizzo Razea line. The same adjustment of the contact line was performed in May in the Adamello group where Cima Presena, Cima Zigolon and almost all the pick of Monticelli were conquered. Thanks to this “battle of the three mounts” the Italian recovery began. Caporetto had been only an episode. In fact, in March, after the beginning of the great German offensive in France, 4 French divisions out of 6 and 2 Britain divisions out of 5 could retreat from the Italian front, without causing any problems; on the contrary, in order to demonstrate the brotherhoods between the Allies, an Italian Army Corps​ was sent to France.​