When discussion turns to the initial settlement of the Jews in the German lands, one thinks of French and Italian Jewish migrants to the Rhineland and, more marginally, to Bavaria in the ninth and tenth centuries. When discussion turns to their linguistic profile, it is invariably Yiddish, allegedly a variant of High German, that comes to mind. These two claims have been at the heart of German-Jewish historiography and Germanic linguistics for some time. And yet both of them, I believe, are essentially erroneous.

Speaking heterogeneous Romance and non-Romance languages, Jews settled in different parts of the German lands, where they developed two indigenous languages: (1) in the extreme southwest, imported Judeo- French was supplanted by a judaized form of High German (which I will call “Ashkenazic German,” following the native-language epithet aškenazes) and, ultimately, by Yiddish; (2) elsewhere, Balkan Jews, presumably speaking Balkan Romance, Slavic, and/or Greek, became speakers of Judeo-Sorbian, which subsequently developed into Yiddish. Contrary to common opinion, the latter is a West Slavic language with an unusually large German vocabulary and is genetically unrelated to High German. An evaluation of the historical contacts between the two Jewish languages — or “Yiddishes” — and Rotwelsch first requires a reassessment of the time and place of the genesis of Ashkenazic German and Yiddish, their component makeups, and their genetic classifications.