It was a seemingly simple document—a brief 1944 letter with text in German and Hungarian that declared that a Jewish woman from Budapest, was under the protection of the Swiss Legation. But for Maria Magdalena Grausz, it meant freedom.

Grausz and over 60,000 other Hungarian Jews were saved from deportation to concentration camps by similar letters, all issued by a diplomat named Carl Lutz. Credited with saving half of Budapest’s Jewish population from the Holocaust, Lutz used paper, not weapons, to fight the Nazis.

Born in Switzerland, Lutz immigrated to the United States as a young man. Then, he became a diplomat, eventually serving at the Swiss Consulate in Mandatory Palestine. Lutz, a strict Methodist, was then transferred to Budapest.

At the time, Hungary was one of the Axis powers aligned with Nazi Germany. Hungarian Regent Miklós Horthy had passed laws restricting the activities and movements of Hungarian Jews. During the early parts of the war, the Hungarian Army committed anti-Jewish pogroms and more than 100,000 Hungarian Jews were forced to work on the battle front in hellish conditions. However, Horthy refused to let Hungarian Jews be deported to extermination camps by the Nazis.

Lutz represented countries that had cut off their diplomatic relations with Hungary because of its German alliance. Troubled by Jews’ precarious situation in Hungary, Lutz began to work with the Jewish Agency for Palestine, a group that helped European Jews get entry to British Palestine. Thousands of of Jews, including 10,000 children, left Hungary with Swiss documents issued by Lutz.

Then, in 1944, things got even worse. When Hitler learned that Horthy had been trying to find a way out of his Axis alliance, he toppled Horthy and put the Arrow Cross Party—a political party that consisted of Hungarian Nazis—in charge. The party began a reign of terror throughout Hungary, forcing Jews into ghettos, deporting them to death camps, and murdering them outright.

Lutz was horrified and tried to negotiate a way to stop the deportations. Against all odds, he got permission to issue protective documents for 8,000 Jews—a tiny fraction of Hungary’s 800,000 Jews—to flee to Palestine under Swiss protection.

He’d only been given permission to issue 8,000 letters, but in an attempt to save as many Jews as possible, Lutz interpreted that mandate as applying to families, not individual people. He issued more and more protective letters, all numbered one to 8000, and members of the Zionist youth underground forged thousands more.

As the Arrow Cross rampaged throughout Budapest, people with Lutz-issued documents crowded into safe houses he helped organize. To prevent them from being raided, Lutz extended Swiss protection to 76 buildings. One of them, a department store called the Glass House, served as a refuge for up to 3,000 Jews and a headquarters for the Zionist underground.

Chaos swirled throughout Hungary as 440,000 Jews were deported to Auschwitz in a two-month period. Others were shot point-blank and thrown into the Danube by the Arrow Cross—and at one point, Lutz even jumped into the river to save a bleeding woman by invoking his Swiss diplomatic powers. But miraculously, Jews with Lutz-issued papers weren’t targeted.

“The Germans are very correct people,” said Eric Saul, founder and executive director of Visas for Life: The Righteous and Honorable Diplomats Project. “They admire discipline and order. So when Nazi commandants saw these letters, they accepted them.” Despite pushback from Nazi and Hungarian officials, he kept working to save more and more Jews.

Then, in November 1944, the Arrow Cross assembled 70,000 Jews and forced them on a death march to various concentration camps in Austria and Germany. Carl Luz and his wife followed along. As the grueling marches continued, they’d pull people out of line whenever an opportunity presented itself, issuing protective documents and taking them under their wing.

“For these people it was the last glimmer of hope, for us, this…was the worst form of spiritual torture,” Lutz later recalled. “We saw the people being lashed with dog-whips and lying in the slime and mud with bloody faces….Whenever possible I would drive alongside these people on their way to the concentration camps to try and show them that there was still hope.”

By the end of World War II, 565,000 Hungarian Jews had been murdered. But though the efforts of Lutz and his co-conspirators, which included diplomats from other countries and Zionist underground members, 62,000 Jews—half of the Jewish population of Budapest—were saved. It’s still unclear how many Jews made it to Budapest safe houses or how many passes were issued or forged.

After the war, Lutz divorced his first wife and married Maria Magdalena Grausz, the woman he helped save in July 1944. He returned to Switzerland—but not to accolades or acclaim.

Today, Lutz’s heroism is clear. But after World War II ended, his actions weren’t celebrated. Switzerland criticized him for overstepping his diplomatic authority, investigated his wartime activities, and blocked his career advancement.

Eventually, his reputation was rehabilitated. But though Lutz has been compared to Oskar Schindler and other Gentiles who used their connections to save Jews, he’s still relatively unknown. Lutz didn’t do it for fame, though: As his stepdaughter Agnes Hirschi says, “The laws of life are stronger than man-made laws….My father always considered his time in Budapest and the rescue of innocent Jews as the most important part of his life.”