By the Middle Ages, large numbers of Jews lived in the Holy Roman Empire and had assimilated into German culture, including many Jews who had previously assimilated into French culture and had spoken a mixed Judeo-French language. Upon assimilating into German culture, the Jewish German peoples incorporated major parts of the German language and elements of other European languages into a mixed language known as Yiddish. However tolerance and assimilation of Jews in German society suddenly ended during the Crusades with many Jews being forcefully expelled from Germany and Western Yiddish disappeared as a language in Germany over the centuries, with German Jewish people fully adopting the German language.
By what time period had many of the Jewish  population joined the Holy Roman Empire? The Jewish populations upon migrating into the German society mingled languages to form what new language?  What cause the tolerance and mixing  into German Society to end for the Jews? What language did many of the Jews speak after the crusades?  What language did the Jews speak prior to assimilating into German culture? After assimilating to German culture, what language did the Jews adopt? When did Jewish assimilation end? What happened to the Jews during the crusades?