Already in 1914 and shortly following the start of the war, representatives of the Austro-Hungarian military authorities and civil offices discussed possible locations for POW camps. As a consequence, several large barrack camps for POWs were erected in Styria during World War I, such as at Feldbach, Lebring and Knittelfeld.
At Feldbach, barracks were built in 1915 for around 2,000 guards and 20,000 prisoners as well as hospital- and isolation barracks, in total approximately 100 buildings. The ground required for this was rented for a period of six years at a cost of 200 crowns per bay. At the end of the war in 1918, a total of 92 hectares had been constructed.
When Italy entered the war in May 1915 the responsible Austro-Hungarian authorities decided to evacuate the Feldbach camp and relocate the POWs to other camps in Hungary. Only the approximately 4,000 prisoners assigned to the construction department of the Feldbach camp remained on site.
A hospital also belonged to the Feldbach POW camp that after relocation of the POWs was expanded to treat around 5,000 injured. During the course of the war it grew to become one of the largest military hospitals in the Danube Monarchy, and was equipped with its own operating theatres, x-ray equipment and an eye hospital. The camp served as an important military production site for the Austro-Hungarian authorities, making commodities such as hand grenade handles, shoe nails, sled runners, targets, snow shovels and fire extinguishing buckets as well as barracks.

A secret railway test section for the complete monarchy was built near the Feldbach camp in World War I. The tracks were later removed but the routes and building constructions remained.