Khayyām’s legacy extends to Europe and the present day. Amir Theilhaber’s chapter studies how Khayyām’s quatrains (rubāʿiyyāt) were canonised in the German-speaking world through the translation of Friedrich Rosen (1856–1935), Die Sinnsprüche Omars des Zeltmachers. Rosen was a diplomat and scholar of Oriental studies, who had an impact on Khayyām studies in Europe. Theilhaber examines Rosen’s life and the role Khayyām played in his intellectual and religious life. One of the many interesting topics that Theilhaber examines is how Rosen sees in Khayyām the ideas of a freethinker openly challenging Islamic religious orthodoxy, seeing in the Persian scientist an “Aryan-Indo-Germanic spirit that seeks cognisance, in a cultural war against the dogma of Semitic ‘Arabianness.’” Theilhaber demonstrates how such perverse antisemitic ideas were rightly refuted by scholars such as Ignaz Goldziher. The discussion shows how scholars in modern times treated nonconformist mediaeval ideas to explain the rise and popularity of antinomian movements. Aside from such original insights, Theilhaber’s chapter elaborates upon Rosen’s collaboration with Persian intellectuals such as Taqī Arānī in Berlin.