One of the most active members of the Bund, a lawyer who, before the War, often defended members of socialist organisations. During World War II, he was a member of the Council to Aid Jews "Żegota" and, from August 1944 until January 1945, was its Chairman.
Read the history of the Council to Aid Jews "Żegota"
He studied law at the Jagiellonian University. Even in his student days, he was politically active - first in the Galicia and Śląsk Cieszyński Polish Social-Democratic Party and later co-founded the Jewish Social-Democratic Party. At that time, he was also editor of that party's organ "Der Socjaldemokrat" and its weekly "Nowe Życie" (New Life). Before the War, he was also involved in the development of Jewish culture and sport. He was Chairman of the Jewish Sports Club "Jutrzenka" in Kraków. He co-founded the Kraków Jewish Theatre Association. Because of his socialist activities, in 1939, he ended up in the Bereza Kartuska prison camp.
In the first weeks of September 1939, he found himself in Soviet-occupied territory. While attempting to cross the Lithuanian border, he was arrested by the NKVD and imprisoned in Lida. Following the Third Reich's invasion of the USSR in June 1941, while the Soviets were retreating from the city, he managed to escape from the prison. He came to Warsaw and lived on the so-called "Aryan side". Straight away, he joined into the underground work of the Bund and became active in the Jewish resistance movement.
In August 1942, he turned to Henryk Woliński, head of the Jewish Department of the Home Army's Bureau of Information and Propaganda, with the request that a telegram be sent to Szmul Zygelbojm, the Bund's representative on the Rada Narodowa RP (National Council of Poland), containing information about the situation of Polis Jews. That telegram was sent on 2nd October 1942.
From that time, Feiner, under the codename "Berezowski", made reports, regarding the situation in the Warsaw ghetto, which found their way to the Polish Government-in-Exile. In October 1942, he also met with Jan Karski. At that time, he made the following appeal:
"We want you to tell the Polish Government and the governments of the Allies and their leaders that we are helpless in the face of German crimes.We cannot defend ourselves alone and no one else in Poland can defend us. The Polish underground authorities are able to save some of us, but they cannot rescue us en masse. The Germans are not trying to make us slaves as they are doing with other peoples - we are being systematically murdered. Our entire people will be destroyed. A few can probably be saved, but the fate of three million Jews is sealed. No force in Poland can prevent it - neither the Polish nor the Jewish underground. Put this responsibility onto the shoulders of the Allies. Do not let it get to the point that any of the leaders of the united nations can say that they did not know that help could only come from the outside. (…) Tell Jewish leaders that this is not a time for politics or tactics.Tell them that the earth should be shaken to its very foundations, that the world needs to be roused. Maybe then, it will wake up, understand and see".
In his reports and letters, he demanded that the Polish Government call upon the Polish people to help the Jews – to provide material help for those still alive, to provide weapons, to punish blackmailers and for a stronger reaction against what was happening in the ghettos.
Feiner took part in discussions with the Government Delegation for Poland on establishing a new organisation to replace the Provisional Committee to Aid Jews. After the Council to Aid Jews "Żegota" was established in December 1942, he became its Deputy Chairman and represented the Bund under the codenames of "Mikołaj" and "Lasocki".
He was a representative of the Komisja Koordynacyjna (Steering Committee), established in the evening of 1st December 1942, the result of an agreement between the Jewish National Committee and the Bund. In January 1943, he became Chairman of the Bund Central Committee.
Władysław Bartoszewski remembered Feiner thus: "Dr Leon Feiner had excellent contacts with the Home Army High Command, with the PPS-WRN and with the Socialist Left. He was the author of one of the most important reports by the Jewish underground to the government in London. Before the War, he was a well-known, prosperous lawyer in Kraków. He was imprisoned in Bereza due to being falsely accused of being a communist. Perhaps that was the reason for one of his codenames, during the occupation, being "Berezowski". He was doubtless a leftist. He was certainly not a communist. He had great communal experience, an immense intellect and a sense of humour. He looked like a country squire with his grey mop of hair and grey moustache – like a provincial noble who had come to the big city, similar to Michał Bałucki or Józef Bliziński from the world of literature".
For a certain period, Feiner hid in the home of actor Aleksandra Zelwerowicz. Following the collapse of the uprising in the Warsaw ghetto, he endeavoured to help those who had ended up in forced labour camps. From August 1944, he was Chairman of the Council to Aid Jews "Żegota". During the Warsaw Uprising until the end of the War, together with members of the Bund and the Home Army, he hid in the partment of Eugenia Wąsowska-Leszczyńska.
He died in Lublin on 22nd February 1945 as the result of cancer. He was buried in the Jewish cemetery on Okopowa Street in Warsaw.