In November 1941, SS and police officials established Treblinka I as a forced labor camp for Jews and Poles in a desolate area near the villages of Treblinka and Malkinia in the Generalgouvernement (the part of German-occupied Poland that had not been annexed to the Reich or to Soviet-occupied territory). Beginning in July 1942, Aktion Reinhard authorities completed the construction of a killing center known as Treblinka II, about a mile away from Treblinka I. Under the initial command of SS 2^nd Lieutenant Dr. Irmfried Eberl, a physician, gassing operations at the Treblinka killing center began on July 23, 1942. The same operations were already underway at the Sobibor and Belzec killing centers. Dr. Eberl was eventually replaced as commander of the camp by SS Captain Franz Stangl, and then SS 2^nd Lieutenant Kurt Franz. Franz proved more adept at processing large numbers of incoming deportees and organizing the structure of the camp killing process.

Due to their proximity to the killing center, deportations to Treblinka came mainly from the Warsaw and Radom ghettos. Between July and September 1942, approximately 265,000 Jews were deported to Treblinka from the Warsaw ghetto. Between August and November 1942, approximately 346,000 Jews were deported from the Radom district. More than 110,000 Jews from the Bialystok District were deported to Treblinka from October 1942 to February 1943. As time went on, additional deportations came from various places in the Generalgouvernement, as well as from Greece, Yugoslavia, Germany, Austria, France and Slovakia.

Deportees were initially told that they had arrived at a transit camp and were to be sent to labor camps after taking a hygienic shower. After handing over all valuables and undressing, the victims were then forced to enter the gas chambers, which were labeled as showers. Initially, the victims’ bodies were buried in mass pits by Jewish prisoners, but were later exhumed and burned in an effort to hide evidence of the killing operation. Having accomplished its mission, Treblinka II was dismantled in the fall of 1943. The labor camp of Treblinka I continued to operate until July 1944, when the remaining Jewish prisoners were shot and killed in anticipation of the impending Soviet advance. It is estimated that between the start of killing operations in July 1942 and their completion in November 1943, approximately 925,000 Jews were murdered at Treblinka.  This number does not include Poles, Roma, and Soviet POWs.