"Jewish speakers of Old French or Old Italian who were literate in either liturgical Hebrew or Aramaic, or both, migrated through Southern Europe to settle in t

"Jewish speakers of Old French or Old Italian who were literate in either liturgical Hebrew or Aramaic, or both, migrated through Southern Europe to settle in the Rhine Valley in an area known as Lotharingia (later known in Yiddish as Loter) extending over parts of Germany and France.[29] There, they encountered and were influenced by Jewish speakers of High German languages and several other German dialects" https://en.wikipedia.org/wiki/Yiddish#Origins https://en.wikipedia.org/wiki/Yiddish#Origins