During World War II, Trawniki men were Eastern European Nazi collaborators, consisting of either volunteers or recruits from prisoner-of-war camps set up by Nazi Germany for Soviet Red Army soldiers captured in the border regions during Operation Barbarossa launched in June 1941. Thousands of these volunteers served in the General Government territory of German-occupied Poland until the end of World War II. Trawnikis belonged to a category of Hiwis, Nazi auxiliary forces recruited from native subjects serving in various jobs such as concentration camp guards.