The decision to create an extermination camp in Bełżec was made on 13 October 1941, during a meeting between Reichsführer-SS Heinrich Himmler, higher commander of the SS and police forces in the General Government SS-Gruppenführer Friedrich Krüger, and commander of the SS and police forces in the Lublin district. Their briefing took place in the Wolf’s Lair near Rastenburg (today Kętrzyn) – Hitler’s main command centre in East Prussia. The location for the future killing centre was made at Globocnik’s headquarters in Lublin.
On 30 October 1941, SS-Hauptsturmführer Richard Thomalla from the SS Central Building Administration in Lublin together with several other officers including Gottfried Schwarz, Josef Oberhauser, and Johann Niemann, arrived in Bełżec to coordinate the camp construction.
Having arrived in Bełżec, the SS functionaries submitted a note to the local administration office demanding that they provide a team of labourers, which were then tasked with building wooden barracks near the railway ramp located at the foot of the Kozielsk hill. Twenty men were dispatched for those works – people from Bełżec and other nearby settlements. They were conducted between 1 November and 23 December 1941. Additionally, they performed tasks aiming at further expansion and creating the organisational structure of the camp.
SS-Obersturmführer Christian Wirth arrived in Bełżec in mid-December 1941, and took command of the camp construction and organisation. He served as its commandant until August 1942.
The final construction works were accomplished by a group of at least 120 Jews from the town of Lubycza Królewska. Then, they were all murdered in the gas chambers. In the following days some small transports of Jews were brought into the camp and used them for testing the efficiency of mass murder in the gas chambers.
On 17 March 1942, the Germans began the mass deportations of Jews to Bełżec. The first transports came from the ghetto in Lublin in the morning, and from Lviv in the afternoon. Those events are considered the beginning of operation “Reinhardt” – the programme of the mass extermination of Jews in the General Government.
The first stage of deportations to SS-Sonderkommando Belzec concluded and the camp ceased its operations for around a month. By mid-April, a total of nearly 80,000 Jews were murdered. They were mostly from various settlements and towns of the Lublin and Galicia districts.
The camp resumed its functioning around 22 May. By the end of the month mostly Jews from nearby ghettos were murdered.
Transports of Jews from the Kraków district were directed to Bełżec from early June. After two weeks, the camp temporarily ceased its operation for the time of expanding the gas chambers.
On 10 September, 8,205 people were deported from Kolomyia to Bełżec, including residents of Kuty, Kosiv, Horodenka, Sniatyn, and Kolomyia. This was the largest transport in the history of the camp’s operation.
