Conspiracy theories have been an important aspect of antisemitism through different historical phases. The representation of the Jew as an evil and disruptive figure, equipped with almost unlimited power, has been a recurrent feature of both premodern, religious anti-Judaism and modern nationalist and racist antisemitism. In the context of the changing political and social landscape of Europe during the ‘long nineteenth century’ of 1789 to 1914, antisemitism adopted new forms and shapes. The ideological content of The Protocols can best be summarised as a combination of antisemitism and anti-modernism. It offered a pseudo-explanation of the perils of modernity, as seen from the viewpoint of the ultraconservative and extreme right. Although conspiracy theories were an integral part of modern, political antisemitism prior to 1914, during and after the First World War European antisemitism underwent radicalisation. In the aftermath of the First World War, conspiracist antisemitism gained a particularly strong influence in Germany.