Gusen, the largest of the satellite camps in the Mauthausen complex in central Austria, operated from March 1940 to May 1945. Inmates working in the camp’s quarries and brickworks were subject to brutal conditions, and around half of the approximately 70,000 prisons who entered one of the three Gusen camps (Gusen II and III were established in 1944) died there. More than 2500 prisoners were sent from Gusen to nearby Schloss Hartheim and killed by gas.