Simon Wiesenthal is born on 31 December 1908 in Buczacz (Butschatsch), which is part of the Austro-Hungarian Empire at the time. During the First World War, his mother flees with her two sons to Vienna, but returns to Buczacz after the war. His father is killed on the Russian front. Wiesenthal initially wants to study architecture in Lviv (then Lemberg), which has become part of Poland. However, due to antisemitic admission restrictions at Polish universities, he is forced to study in Prague instead. In 1936, he marries his school friend, Cyla Müller, and opens an architectural office in Lviv.

Following the Hitler–Stalin Pact in 1939, the region is annexed by the Soviet Union and Wiesenthal loses his office. After the German invasion of the Soviet Union in 1941, the Jewish population experiences unprecedented terror. Wiesenthal is arrested and deported to the Janowska forced labour camp. He is subsequently interned in various camps and ghettos, including Płaszów and Auschwitz. His wife survives by assuming a false identity. In May 1945, Wiesenthal is liberated from the Mauthausen concentration camp by US troops, severely weakened.

Immediately after being liberated, he begins collecting testimonies and documents on Nazi crimes. Initially working for the US authorities, he supports survivors in searching for relatives and seeks to raise public awareness of their traumatic experiences. In Linz, he establishes the Jewish Historical Documentation Centre, which supports initial investigations and forwards information about Nazi perpetrators to Allied authorities. However, the onset of the Cold War and the Austrian State Treaty lead to a decline in official interest in systematic prosecution. Many investigations are discontinued or remain inconclusive. Frustrated by this, Wiesenthal sends a large part of his materials to the Yad Vashem memorial in Jerusalem.

The capture of Nazi criminal Adolf Eichmann in Argentina in 1960 brings Wiesenthal sudden international recognition. He has collected information for years and passing it on to the Israeli authorities. The global media coverage of the Jerusalem trial brings renewed attention to his work. Building on this momentum, Wiesenthal founds the Documentation Centre of the Association of Jews Persecuted by the Nazi Regime (BJVN) in Vienna. Over the following decades, he researches Nazi perpetrators internationally, passing information on to the relevant authorities and providing journalists, historians and legal experts with material.

He also contributes to the initiation of numerous legal proceedings. His work, however, takes place under extremely difficult circumstances. The Documentation Centre receives no state funding and public sentiment in Austria is often hostile. Wiesenthal and his wife are subjected to insults and threats, and in 1982, they narrowly escape a bomb attack on their apartment in Vienna. He also encounters significant political opposition. In 1975, he has a public disagreement with Chancellor Bruno Kreisky after drawing attention to the Nazi past of FPÖ politician Friedrich Peter. Kreisky publicly attacks Wiesenthal, accusing him of having had links to the Gestapo.

This confrontation is emblematic of how Austria deals with its Nazi past well into the 1980s. Despite these obstacles, Wiesenthal becomes a leading international voice in the process of coming to terms with the past. He is an active lecturer and author who publishes books, advises filmmakers and journalists, and strengthens dialogue between survivors, scholars and the general public.

His motto ‘Justice, not revenge’ encapsulates his persistent principle and shapes his self-understanding as a documentarian rather than an avenger. After 1945, Wiesenthal keeps in close contact with numerous survivors, who provide him with information about perpetrators, missing relatives and local events. He documents these leads with the same meticulousness as his own investigations, gradually building up an extensive archive on individuals, crime scenes and networks of crimes associated with National Socialism.

Until his death in 2005, Wiesenthal devotes himself to researching Nazi crimes, supporting survivors and raising public awareness of antisemitism and the persistence of racism. Over the course of his life, he identifies around 3,000 perpetrators, and more than one-third of these cases result in investigations or court proceedings. His extensive archive, comprising approximately 8,000 files, almost all of his correspondence and personal documents, is now preserved and catalogued at the Vienna Wiesenthal Institute for Holocaust Studies (VWI). It forms a central foundation for research and stands as a testament to the ways in which the crimes of National Socialism have been addressed.