Any of the historically Yiddish-speaking European Jews who settled in central and northern Europe, or their descendants. They lived originally in the Rhineland valley, and their name is derived from the Hebrew word Ashkenaz (Germany). After the start of the Crusades in the late 11th century, many migrated east to Poland, Lithuania, and Russia to escape persecution. In later centuries Jews who adopted the German-rite synagogue ritual were called Ashkenazim to differentiate them from the Sephardic, or Spanish-rite, Jews (seeSephardi), from whom they differ in cultural traditions, pronunciation of Hebrew, and synagogue chanting as well as in the use of the Yiddish language (until the 20th century). Today they constitute more than 80% of the world's Jews.