Alexander Pechersky was the leader of the most successful mass-escape of Jews from which Nazi camp?

Alexander 'Sasha' Pechersky (Russian: Алекса́ндр Аро́нович Пече́рский; 22 February 1909 – 19 January 1990) was one of the organizers, and the leader, of the most successful uprising and mass-escape of Jews from a Nazi extermination camp during World War II; which occurred at the Sobibor extermination camp on 14 October 1943.

In 1948, Pechersky was arrested by the Soviet authorities along with his brother during the countrywide Rootless cosmopolitan campaign against Jews suspected of pro-Western leanings but released later due in part to mounting international pressure. However, the harassment did not stop there. Pechersky was prevented by the Soviet government from testifying in multiple international trials related to Sobibor, including the Eichmann Trial in Israel. The last time he was refused permission to exit the country and testify was in 1987, for a trial in Poland.

Sobibor (/soʊˈbiːbɔːr/) was a Nazi German extermination camp built and operated by the SS during World War II near the railway station of Sobibór near Włodawa within the semi-colonial territory of General Government of the occupied Poland.

The camp was part of the secretive Operation Reinhard, the deadliest phase of the Holocaust in Poland. Jews from Poland, France, Germany, the Netherlands, Czechoslovakia, and the Soviet Union (including Jewish-Soviet POWs), were transported to the camp by rail. Most were suffocated in gas chambers fed by the exhaust of a large petrol engine.