In addition, at the end of the war it successfully fought to keep passes into Austria open, allowing German units to escape the Balkans and surrender to British forces.

In mid-1942, the Waffen-SS formed a company intended for anti-partisan operations in the rugged and high-altitude border region between Italy, Austria and Yugoslavia known as the Karst.

[4] The unit drew its recruits mainly from among the Germans of Yugoslavia (Volksdeutsche) and South Tyroleans,[8] with the officer cadre being drawn from SS geological detachments.

[5] The battalion-strength Waffen-SS Geological Corps (German: SS-Wehrgeologenkorps), from which such detachments were drawn, was formed in April 1941 and consisted mainly of engineers with a few geologists.

From October 1943 until June 1944, the battalion was based at Gradisca d'Isonzo in Italy, and participated in anti-partisan operations in the areas of Trieste, Udine and the Istrian peninsula.

Early in 1944, Brandt suggested that Slovene nationalists be recruited into the battalion, but the idea was rejected by SS headquarters who feared that such a policy would allow the infiltration of the unit by Yugoslav Partisans.

During March 1944, the battalion was involved in a rapid series of operations, including Zypresse (Cypress), Märzveilchen (Violet), Maulwurf (Mole) and Hellblau (Light Blue), resulting in significant guerrilla casualties, as well as executions of captured partisans.

[4] The name Karstjäger was derived from a combination of Karst, denoting the region of operations, and Jäger, the German military term for light infantry.

[17] During late 1944 and early 1945, the Waffen Mountain (Karstjäger) Brigade of the SS fought first against British-supported partisans in the Julian Alps, and was then deployed to the coastal area around Trieste and the Marano-Grado Lagoon.

In danger of being cut off by Allied forces, the brigade soon returned to the Julian Alps, having to fight its way through the Tagliamento river valley between Osoppo and Gemona.

[19] In the final weeks of the war the brigade was part of a Kampfgruppe (battlegroup) commanded by SS-Brigadeführer und Generalmajor der Waffen-SS (Brigadier) Heinz Harmel, which was ordered to keep the Karawanks passes open between Yugoslavia and Austria.

[21] A joint Italian-German study implicated members of the division in 23 crimes involving the killing of 277 people in Italy between the Armistice of Cassibile and the end of World War II.