This essay inaugurates the historical study of the modern homosexual Jewish experience before Stonewall. I begin with a historiographic introduction to the emerging subfield of gay Jewish history. I then turn to reintroduce Jiri Langer, a homosexual and Hasidic writer affiliated with the interwar "Prague circle" (and friend of Franz Kafka and Max Brod) into the purview of modern Jewish Studies. I take up two questions: first, how Langer reconciled his homosexual and Orthodox religious identity; and second, why Langer"s homosexuality became exigent as a Jewish question at this particular historical moment. In his key text, Die Erotik der Kabbala, Langer engages with the dominant interwar debates on homosexuality, but most directly with the work of Hans Blüher, the major theoretician of the German Wandervogelbewegung. In the course of correcting Blüher's antisemitic claims about Jews and homosexuality, Langer managed to delineate a specifically homosexual Jewish identity by renegotiating the relationship between homosexuality and Judaism and by adumbrating a history of "gay" Jews. I contextualize this long-neglected text within Langer's fascinating biography; the debates in the early homosexual rights movement; the particular cultural features of the "Prague circle" in which Langer wrote; and the dislocation and devastation of Langer's beloved eastern-European Hasidic communities caused by World War I—communities that Langer experienced as deeply homoerotic.