In the basement of the world’s oldest archive of the Holocaust, located in a townhouse on Russell Square in London, the latest artefact to join the Wiener Holocaust Library’s collection leans against a wall. It is a metal sign that had been attached to the building’s front railings until early November when it was brought downstairs after staff arriving at work found it daubed with the word “Gaza” in red paint. “It is quite bulky so I don’t think anyone’s worked out where it is going to be stored”, said the head curator, Dr Barbara Warnock. There had been similar examples of antisemitic graffiti found around the capital in the weeks after the 7 October attacks in Israel. “I assume it was coordinated,” Warnock said of the defacing of schools, bus stops and synagogues at the time. “I don’t think the police have managed to identify anyone as far as I’m aware – at least not that I’ve heard.” It marks a dispiriting start to next week’s 90th anniversary of the library’s establishment, something that is being commemorated in London with an exhibition of some of the archive’s most significant objects, and in Amsterdam with the installation of new Stolpersteine (stumbling stones), concrete cubes with metal plates, engraved with the names of Kurt Zielenziger and Bernhard Krieg, who died in the Bergen Belsen concentration camp. They had worked at the library’s predecessor, the Jewish Central Information Office (JCIO), after it was established in Amsterdam in 1934 by Dr Alfred Wiener, a German Jew who had left his home country with his family after Hermann Göring personally told him that he was no longer welcome. Wiener had been warning since 1919 of the rise of antisemitism in Germany and had shown extraordinary foresight about the threat the Nazis posed even when they appeared a spent force in the mid-1920s. A third Stolperstein is being installed for Wiener’s wife, Dr Margarete Wiener-Saulmann, who also worked at the JCIO. She and her three daughters did not receive the visa they needed in time to join Wiener in London, where he had fled from Amsterdam with the collection before the German invasion of Holland in 1940. Margarete died on 21 January 1945 as a train was taking her to Switzerland from the Bergen Belsen concentration camp as part of a prisoner swap. Her daughters, including Mirjam Wiener, the mother of the Conservative peer and journalist Daniel Finkelstein, survived. Wiener’s collection was not just a warning. When Adolf Hitler’s deputy, Rudolf Hess, flew solo to Scotland in an attempt to negotiate a peace proposal, the library provided evidence of who he was and his past actions. It provided intelligence on the Möhne dam to assist with the Dambusters raid, including maps of the area. Today it remained as relevant as ever, said Warnock. The rise in antisemitic and Islamophobic attacks since October had been difficult, she said, but it had not come out of a vacuum. The period during which Jeremy Corbyn led the Labour party was deeply uncomfortable while the Covid pandemic was an excuse for the dissemination of a whole new wave of antisemitic conspiracy theories, she added. Among the pieces on show for the next week are a pamphlet published by the JCIO on London in 1945, which is one of the earliest accounts from a survivor of the Auschwitz death camp. Mordechai Lichtenstein, born in Bendzin in Poland in 1912, chronicled the workings of the camp, and noted the particularly murderous intent of the guards after hearing the latest speeches from Hitler and Goebbels over the wireless. There are also drawings on display from children who witnessed the genocide in Darfur, western Sudan. Warnock said they were, at heart, an organisation concerned with the plight of refugees. Of the exhibition, Warnock said: “I think we’re hoping to make people aware of us, aware of the history aware of the quality and depth and range of the collections, and its significance to Britain. “With our history as a refugee organisation, we are also concerned about, you know, rhetoric, and sometimes policy around refugees as well. There’s a lot to be concerned about.”