The theory that Jesus of Nazareth spoke and taught exclusively in Aramaic rather than Hebrew achieved its present dominant position just over a century ago due largely to the labour of Gustaf Dalman. His primary motivation was not the recovery of the historical Jesus, however, but to support his deep commitment to the Protestant movement to convert Jews. This movement did not escape the impact of escalating anti-Semitism in society, intensified by rapid progress towards German national unification. One Christian response to anti-Semitism was to "extract" Jesus from Judaism by contrasting him with "Jewish" attitudes and values held by Jewish spiritual authorities. Dalman's contribution was to extract Jesus from the ethnically exclusive Hebrew language by insisting that he spoke only the more widely-used lingua franca of the region, Aramaic. By over-stating his case and going beyond the evidence, Dalman revealed his indebtedness to the anti-Semitic spirit of his age.