The Battle of the Alps was an opening engagement of World War II. It unfolded concurrently with the Bohemian Campaign and marked Germany’s second major victory against the Eurasian Axis. Unlike the regular Deutsches Heer units employed in Bohemia, the Alpine offensive was carried out largely by militia Freikorps formations, of which the majority belonged to the Waffen SS. These irregular troops lacked regular training, heavy weaponry, and logistical support, yet they proved unexpectedly effective against the disorganised Danubian Army, whose morale was collapsing amidst political division and civil unrest.
As in Bohemia, local populations played a decisive role. In Austria, mass uprisings erupted against the socialist government, driven by strong pro-German and monarchist sympathies. German forces advancing through the Alpine passes received widespread support from Austrian civilians, whose revolts crippled Danubian supply routes and forced many army units into retreat or surrender. By the last days of 1939, Vienna had fallen, and it was proclaimed the capital of the newly organised Danubian Restoration Army, which sought to re-establish a constitutional Habsburg monarchy aligned with the West.
German momentum slowed as the offensive pushed eastward. Attempts to penetrate into Hungary met with heavy resistance, both from entrenched Danubian units still loyal to the socialist government and from reinforcements provided by the South European Pact (SEUROP). The fighting along the Austrian-Hungarian frontier devolved into a series of attritional battles, culminating in the protracted Battles of the Pannonian Plain. These engagements marked the end of Germany’s rapid early victories and signalled the beginning of a more costly, drawn-out campaign in Central Europe.