Ashkenaz is the medieval Hebrew name for the German lands, and the communities that formed there in the tenth and eleventh centuries, above all Speyer, Worms and Mainz, the ShUM cities, became the root of a distinct Jewish civilization. Its scholars fixed a liturgical rite and a body of legal custom, minhag Ashkenaz, that its descendants carried everywhere; its martyrs of the First Crusade massacres of 1096 shaped a liturgy of remembrance; and its vernacular, Yiddish, fused medieval German with Hebrew, Aramaic and later Slavic elements into the language of a thousand years of daily life.
From the thirteenth century, expulsion and opportunity drew Ashkenazi Jews eastward into Poland and Lithuania, where charters of protection and communal self-government, the kahal and the Council of Four Lands, allowed the largest Jewish population in the world to grow. The market town with its synagogue, study house and cemetery, the shtetl of later memory, became the setting of Ashkenazi life, documented in exhaustive detail by the YIVO Institute founded in Vilna in 1925.
The nineteenth century brought the Haskalah, the Jewish enlightenment, mass emigration westward after the pogroms of 1881, and the growth of Zionism, socialism and secular Yiddish culture as rival answers to modernity. The Holocaust murdered most of European Jewry and ended the Eastern European heartland; its surviving branches, in Israel, the United States and beyond, now carry the Ashkenazi inheritance.