Throughout the Spring and Summer of 1917, the Italians had launched numerous offensives on the Austro-Hungarian Lines in the Isonzo Sector, with The 11th Battle of the Isonzo being the most successful in pushing back the Austro-Hungarians.
After the Italian success in the 11th Battle of the Isonzo, Emperor Karl knew a breakthrough was going to happen at any moment, as both the Austro-Hungarians and Italians were exhausted, and running out of men to sustain the war.
So, he wrote to Kaiser Wilhelm II and requested that German Forces be deployed to Italy.

In August 1917 Paul von Hindenburg decided to send troops from the Eastern Front to the Isonzo Sector.
Erich Ludendorff was opposed to this but was overruled.
Later, in September three experts from the Imperial General Staff, led by the chemist Otto Hahn, went to the Isonzo front to find a site suitable for a gas attack.
They proposed attacking the quiet Caporetto sector, where a good road ran west through a mountain valley to the Venetian Plain.

The Austro-Hungarian Army Group Boroević, commanded by Svetozar Boroević, was prepared for the offensive.
In addition, a new 14th Army was formed with nine Austrian and six German divisions, commanded by the German Otto von Below.
The Italians inadvertently helped by providing weather information over their radio.
Throughout the Spring and Summer of 1917, the Italians had launched numerous offensives on the Austro-Hungarian Lines in the Isonzo Sector, with The 11th Battle of the Isonzo being the most successful in pushing back the Austro-Hungarians. After the Italian success in the 11th Battle of the Isonzo, Emperor Karl knew a breakthrough was going to happen at any moment, as both the Austro-Hungarians and Italians were exhausted, and running out of men to sustain the war. So, he wrote to Kaiser Wilhelm II and requested that German Forces be deployed to Italy.
In August 1917 Paul von Hindenburg decided to send troops from the Eastern Front to the Isonzo Sector. Erich Ludendorff was opposed to this but was overruled. Later, in September three experts from the Imperial General Staff, led by the chemist Otto Hahn, went to the Isonzo front to find a site suitable for a gas attack. They proposed attacking the quiet Caporetto sector, where a good road ran west through a mountain valley to the Venetian Plain.
The Austro-Hungarian Army Group Boroević, commanded by Svetozar Boroević, was prepared for the offensive. In addition, a new 14th Army was formed with nine Austrian and six German divisions, commanded by the German Otto von Below. The Italians inadvertently helped by providing weather information over their radio.
Battle of Caporetto