Many of the former SS staff who survived the typhus epidemic were tried by the British at the Belsen trial. Over the period in which Bergen-Belsen operated as a concentration camp, at least 480 people had worked as guards or members of the commandant's staff, including around 45 women.[27] From September 17 to November 17, 1945, 45 of those were tried by a military tribunal in Lüneburg. They included former commandant Josef Kramer, 16 other SS male members, 16 female SS guards and 12 former kapos (one of whom became ill during the trial).[28] Among them were Irma Grese, Elisabeth Volkenrath, Hertha Ehlert, Ilse Lothe [de], Johanna Bormann and Fritz Klein. Many of the defendants were not just charged with crimes committed at Belsen but also earlier ones at Auschwitz. Their activities at other concentration camps such as Mittelbau-Dora, Ravensbrück, Neuengamme, the Gross Rosen subcamps at Neusalz and Langenleuba, and the Mittelbau-Dora subcamp at Gross Werther were not subject of the trial. It was based on British military law and the charges were thus limited to war crimes.[28] Substantial media coverage of the trial provided the German and international public with detailed information on the mass killings at Belsen as well as on the gas chambers of Auschwitz-Birkenau.[28]

The camp changed its name to Bergen-Belsen and was converted into a concentration camp in 1943. Jews with foreign passports were kept there to be exchanged for German nationals imprisoned abroad, although very few exchanges were made. About 200 Jews were allowed to immigrate to Palestine and about 1,500 Hungarian Jews were allowed to immigrate to Switzerland, both took place under the rubric of exchanges for German nationals.

The mass killings of Jews in the occupied Soviet territories were assigned to four SS formations called Einsatzgruppen ("task groups"), which were under Heydrich's overall command. Similar formations had been used to a limited extent in Poland in 1939, but the ones operating in the Soviet territories were much larger.[242] The Einsatzgruppen's commanders were ordinary citizens: the great majority were professionals and most were intellectuals.[243] By the winter of 1941–1942, the four Einsatzgruppen and their helpers had killed almost 500,000 people.[244] The largest massacre of Jews by the mobile killing squads in the Soviet Union was at a ravine called Babi Yar outside Kiev,[245] where 33,771 Jews were killed in a single operation on 29–30 September 1941.[246][n] A mixture of SS and Security Police, assisted by Ukrainian police, carried out the killings.[248] Although they did not actively participate in the killings, men of the German 6th Army helped round up the Jews of Kiev and transport them to be shot.[249] By the end of the war, around two million are thought to have been victims of the Einsatzgruppen and their helpers in the local population and the German Army. Of those, about 1.3 million were Jews and up to a quarter of a million Roma.[250]
At the Bergen-Belsen camp, a sign had been put up outside the gate to warn the British liberators that there was typhus in the camp, but there was no sign at Dachau since there was no danger to the Americans who had all been vaccinated against typhus and other diseases before going overseas. The American liberators assumed that the emaciated bodies that they found piled up in the camp were the bodies of prisoners who had been deliberately starved to death.
This photo was taken in April 1945, after liberation. Originally designed as a prisoner of war and transit camp, Bergen-Belsen was to house 10,000 prisoners. From March 1944, Bergen-Belsen became a "regular concentration camp" with new prisoners arriving who were too sick to work at other camps. Some 35,000 to 40,000 inmates died of starvation, overcrowding, hard labor and disease or were killed.
The staff consisted of a chief, several assistants and a group of clerks. The office maintained files which contained all personal data pertinent to the allocation of individuals for work of various kinds. The three main sources of employment at Dachau were (a) work inside the camp, (b) work at the SS camp, (c) work in farms and in factories in the area. The lists of people to be shipped off on transports was usually compiled from those prisoners who were not part of a regular "Working Commando."
In the summer of 1943, Stalag XI-C (311) was dissolved and Bergen-Belsen became a branch camp of Stalag XI-B. It served as the hospital for all Soviet POWs in the region until January 1945. Other inmates/patients were Italian military internees from August 1944 and, following the suppression of the Warsaw Uprising in October 1944, around 1,000 members of the Polish Home Army were imprisoned in a separate section of the POW camp.[6]