On January 24, 1943, the only train ever to transport non-Jewish women of the French Resistance to the Nazi death camps pulled out of Compiègne station, in northern France. On board were 230 women aged between 17 and 67. Many of them were members of the French Communist Party, which the Nazis feared as the sole organization capable of rallying those in search of a political cause. Prior to their arrest, many of them had sheltered resisters, propagated anti-German pamphlets, hidden weapons, manipulated explosives, and, in at least one case, executed known Nazi collaborators.

Women in Marseille raise the rifles and pistols they used to fight the Nazi garrison before the entry of Allied troops.

The story of these indomitable women, 49 of whom miraculously survived the war, is told in the new French documentary Matricule 31000, le Courage de l’Ombre (Registration No. 31000, the Courage of Shadow). The film is so named because each of the women had numbers between 31625 and 31854 tattooed on their left forearms when they arrived at Auschwitz-Birkenau on January 27, 1943. Their courage, as the film’s title also suggests, existed in the shadows for many years and is only now being fully recognized, eight decades on.

“In the popular imagination, it was the women who carried messages or hid English pilots,” says Frédéric Tonolli, who co-directed the film with his daughter Niagara Tonolli. “But we now know that they were also fighters who put themselves in the firing line.” The documentary, which premiered on the French television channel Histoire TV earlier this year, drew praise from newspapers including Le Monde and Le Figaro for judiciously combining archival interviews featuring several of the convoy’s survivors (the last to die was Christiane “Cécile” Charua in 2016, aged 101) and their descendants, with drawn sequences by Charles Sansonetti.

An illustration from the film.

“I asked Charlie to create images for everything that we don’t have a trace of anymore,” says Tonolli, whose long career as a documentary filmmaker for television included winning the prestigious Prix Albert-Londres for Les Seigneurs de Behring, his 1996 documentary about an Indigenous community living in the Arctic. One of the scenes drawn by Sansonetti in Matricule 31000, le Courage de l’Ombre recaptures the extraordinary moment when the 230 women first entered the gates of Auschwitz-Birkenau and began to sing the “Marseillaise” in unison. “It sounds too good to be true, as though it was a scene from a film,” Tonolli says. “But it really did happen, and the Germans were left completely gobsmacked.”

“In the popular imagination, it was the women who carried messages or hid English pilots. But we now know that they were also fighters who put themselves in the firing line.”

One of the most valuable sources for the Tonellis’ documentary, which was co-produced and narrated by the French journalist and TV personality Marie Drucker, was the memoirs of Charlotte Delbo, whose book, Le Convoi du 24 Janvier (published in English as Convoy to Auschwitz), uses stark, precise prose to describe the horrors of Auschwitz. “It became a sort of Bible for me,” Tonolli says. “In a way I fell in love with this woman and her story, which I would eventually like to turn into a feature. I was astounded by her courage and will to survive.”

The women who were deported to the Ravensbrück extermination camp during W.W. II are welcomed at the headquarters of the Union of French Women, April 18, 1945. A portrait of the Communist activist Danielle Casanova, who died in Auschwitz in 1943, hangs above them.

Delbo credited her own survival and that of the other 48 women on the unstinting solidarity that they showed each other under the most trying circumstances. “A lot of these women knew each other from before,” Tonolli says. “Many of them were hard-line Communists. They had fought for women’s rights before the war and set up Resistance cells together during it.” After the war, many of them spoke out about what they had witnessed of the Holocaust: trucks full of naked corpses piled on top of each other, fields full of human-bone fragments, and the furnaces that burned human bodies and belched out thick smoke from their chimneys.

When the 230 women first entered the gates of Auschwitz-Birkenau, they began to sing the “Marseillaise” in unison.

What still remains a mystery, though, is why these women were sent to Auschwitz in the first place. “Historians still don’t know if it was an error or whether it was because there was a real desire to punish these women for what they had done,” Tonolli says. “We know that Auschwitz was an extermination camp and that other Frenchwomen were taken there because they were Jewish. But these were non-Jewish women working for the Resistance.”

A harrowing scene from the film.

However, what this documentary does make achingly clear is that life for the children of those Frenchwomen who died at Auschwitz would be one of perpetual longing. There is an unforgettable interview with the nearly 90-year-old French artist Michel Politzer, whose mother, Maї, perished in the Polish death camp and whose father, Georges, was executed by firing squad. “It will never, ever pass,” Politzer says in the film. “I don’t know what it means to grieve. It’s something that I detest, this idea that one grieves. I still live with them.”

Matricule 31000, le Courage de l’Ombre, is available for streaming on Histoire TV, in France, and via V.P.N.

Tobias Grey is a Gloucestershire, U.K.–based writer and critic, focused on art, film, and books