Marcel Marceau was known worldwide as a master of silence. The world-famous mime delighted audiences for decades as “Bip,” a tragicomic figure who encountered the world without words. But during World War II, his skills as a mime came in handy for another reason: He used them to save Jewish children during the Holocaust.

Marceau was recruited to help the French Resistance by his cousin, Georges Loinger, a commander in the secret unit who was part of the Oeuvre de Secours aux Enfants, a Jewish relief group that smuggled Jewish children from occupied France to neutral countries. Loinger, who was credited with saving around 350 children, died on December 28, 2018 at the age of 108.

Their mission was to evacuate Jewish children who had been hiding in a French orphanage and get them to the Swiss border, where they would sneak to safety. But traveling with large groups of children was anything but easy. Marceau had a secret weapon: His training as a mime.

“The kids loved Marcel and felt safe with him,” Loinger told the Jewish Telegraph Agency in 2007, after Marceau’s death. “He had already begun doing performances in the orphanage, where he had met a mime instructor earlier on. The kids had to appear like they were simply going on vacation to a home near the Swiss border, and Marcel really put them at ease.”

Marceau, who was Jewish, didn’t just use his acting skills to make the kids comfortable: He used them to save their lives. He mimed “to keep children quiet as they were escaping,” Philippe Mora, the son of one of Marceau’s Resistance comrades, told The Age. “It had nothing to do with show business. He was miming for his life.”

The actor also posed as a Boy Scout leader to trick the authorities. “I went disguised as a Boy Scout leader and took 24 Jewish kids, also in scout uniforms, through the forests to the border, where someone else would take them into Switzerland,” he recalled in 2002. And when he unexpectedly ran into a group of German soldiers near the end of the war, he pretended he was a member of the French Army and demanded they surrender. They did—all 30 of them.

Marceau’s exploits were just a few of the daring, and creative, feats pulled off by the French Resistance. The OCE was particularly ingenious: For example, while smuggling children over the border, one Resistance fighter realized that Nazis never searched sandwiches that had mayonnaise on them since the oily condiment might dirty their uniforms. As a result, they hid children’s ID cards in mayonnaise-smeared sandwiches. And Loinger was able to get Jewish children over the Swiss border by throwing a ball and telling them to retrieve it.

Born Marcel Mangel before the war, Marceau saved at least 70 children. In addition to his border crossing feats, he also forged identity documents to make Jews look younger so they’d be allowed to flee Nazi deportation.

After the war, he changed his name and soon skyrocketed to fame as the world’s most prominent pantomime artist. People connected to the universality of his character, Bip—and his pathos. Part of that sadness stemmed from a very personal loss during the Holocaust. In 1944, Marceau’s father, Charles Mangel, was murdered at Auschwitz.

“I cried for my father,” recalled Marceau in 2002, but I also cried for the millions of people who died….Destiny permitted me to live. This is why I have to bring hope to people who struggle in the world.”