The remains of a fallen Italian soldier on Monte San Gabriele, killed during the 11th Battle of the Isonzo, November 4, 1917.

The remains of a fallen Italian soldier on Monte San Gabriele, killed during the 11th Battle of the Isonzo, November 4, 1917.

Today 106 years ago, on August 18, 1917, the 11th Battle of the Isonzo began, the last Italian-launched Isonzo offensive, but also one of the most successful, yet bloody ones.

By August 1917, the Russians were being pushed far back on the Eastern Front, and the British and French were struggling in the Third Battle of Ypres on the Western Front. 

Ever since the 10th Battle of the Isonzo ended in June 1917, the Italians had prepared for another large offensive on the Isonzo, which would help their allies and hopefully break the Isonzo deadlock.

The Italians would attack across the whole front but would concentrate their efforts north on the Bainsizza Plateau, an attack which would be carried out by the Italian 2nd Army.

It was hoped a breakthrough here would out-flank the entire Austro-Hungarian lines, and the Italian 3rd Army would then attack further south on the Carso Plateau and advance to the city of Trieste.

The two Italian Armies totalled 51 Divisions - some 600,000 troops - along with 5,200 artillery guns. The Italians would also deploy their Arditi assault troops for the first time. Opposing them was the Austro-Hungarian 5th Army with 18 Divisions, being outnumbered more than 2:1 in troops, with just 2,200 artillery guns.

On August 18, 1917, following an intense artillery bombardment, the Italians attacked across a 30-mile front on the Isonzo.

The Italians at Bainsizza captured the first lines of trenches and began crossing the Isonzo, but the Austro-Hungarians disrupted 8/14 of the planned bridges.

The Italians nevertheless still advanced and had opened up a mile-wide gap in the Austro-Hungarian by August 23, forcing them to retreat and abandon the Bainsizza Plateau.

The Italian 3rd Army, attacking on the Carso Plateau, did make some progress, but it came at a great cost of life and against determined Austro-Hungarian resistance.

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The Italians were unable to capture the Monte Ermada on the Carso Plateau, and it was already acknowledged on August 23 that a decisive breakthrough here was impossible.

On August 24, on the Bainsizza Plateau, the Italians captured the Monte Santo, but it became increasingly difficult for them to advance due to poor roads and a lack of artillery shells.

On August 29, the Italians therefore suspended the offensive at Bainsizza and the Carso, and redirected their efforts to the northeast of Gorizia, namely the Monte San Gabriele.

On September 4, the Italians attacked the Monte San Gabriele and captured it, and a violent clash for the summit ensued. 

By September 12, the mountain had switched possession 9 times, and had ended in an Austro-Hungarian victory. This marked the end of the 11th Battle of the Isonzo.

In the 11th Battle of the Isonzo, the Italians had suffered a staggering 158,000 casualties, of whom 30,000 were killed, 108,000 were wounded and 20,000 were missing or taken prisoner. The Italians had achieved great territorial succes on the Bainsizza Plateau, but had been unable to decisively break the deadlock.

The Austro-Hungarians had suffered some 120,000 casualties, of whom 20,000 were killed, 45,000 were wounded, 30,000 were missing and 20,000 were taken prisoner.

After this battle, the Austro-Hungarian lines were on the brink of collapse due to the high losses, thus the Germans sent reinforcements, who would play a decisive role in the 12th Battle of the Isonzo the following month.