Operation Höss

Operation Höss (Aktion Höss) was the codename for the mass deportation of Hungarian Jews and their murder in the gas chambers of Birkenau extermination camp as part of the Holocaust. Between 14 May and 9 July 1944, 420,000 Jews were deported to Auschwitz from Hungary, or about 12,000 per day. About twenty-five percent of each transport was selected for forced labor; the rest were immediately gassed.

The name came from Rudolf Höss, who returned as the commandant of Auschwitz to increase the killing capacity and ensure the transports could be accommodated. After the war, SS official Adolf Eichmann, who had organized the deportations, said that Operation Höss was "an achievement never matched before or since."

Following the murder of Soviet Jews by Einsatzgruppen death squads and the killing of most Polish Jews in Operation Reinhard, Hungary had the largest Jewish population in occupied Europe with almost a million Jews. However, the Hungarian fascist regent, Miklós Horthy, had been reluctant to deport Jews because he suspected that Germany would lose the war and was trying to make a separate peace with the Allies. In order to preempt this possibility, Germany invaded Hungary on 12 March 1944. SS official Adolf Eichmann was sent in with a staff of 100 in order to supervise the deportation of Hungary's Jewish population.

British Prime Minister Winston Churchill described the deportation and murder of Hungarian Jews as "the greatest and most horrible crime ever committed in the whole history of the world."

Diplomatic pressure on Horthy caused him to order a halt to deportations on 7 July.

Of the 437,000 Hungarian Jews deported as part of Operation Höss, only about 50,000 survived the war.