Climbing and skiing became essential skills for the troops of both sides and soon Ski Battalions and Special Climbing units were formed. In 1918, after Austrian defeat at the Battle of Vittorio Veneto, Italian troops ended the war with Austria-Hungary by penetrating deep in South Tyrol. The annexation was confirmed by the Treaty of Saint-Germain. The areas around Trento formed Italian-speaking Trentino. In the north the region around Bozen/Bolzano were inhabited by ethnic Germans and Ladins (today Ladin is the third official language of South Tyrol, alongside German and Italian).

Fascist rule and World War II

After the rise of Fascism in 1922 a policy of Italianization was implemented. All places, down to the tiniest hamlet, were given Italian names, and even family names were translated. The process intensified in the 1930s, when the government of Benito Mussolini encouraged thousands of southern Italians to relocate to the region. Hitler did not claim the German speaking South Tyrol for his “Reich", because Mussolini was too important as an ally. In 1939, both dictators agreed to give the German population a choice: they could emigrate to Germany (or its new territories) or stay in Italy and accept their complete Italianization. It was a difficult choice for the people of South Tyrol: between their language or the landscape where their ancestors had lived. Both solutions meant the crackdown of their culture. As a consequence, South Tyrolen Society was deeply riven. Those who wanted to stay ("Dableiber"), were condemned as traitors, those who left ("Optanten") were defamed as Nazis. Because of the outbreak of the WWII, this agreement between Mussolini and Hitler was never fully accomplished.

In 1943, after the deposition of Mussolini and the capitulation of Italy, German troops invaded Northern Italy. South Tyrol became part of the “Operationszone Alpenvorland". Many German-speaking South Tyroleans wanted revenge upon Italians living in the area, which was mostly stemmed by the occupying Nazis, who still considered Mussolini head of the “Repubblica di Salò".