Yiddish language, one of the many Germanic languages that form a branch of the Indo-European language family. Yiddish is the language of the Ashkenazim, central and eastern European Jews and their descendants. Written in the Hebrew alphabet, it became one of the world’s most widespread languages, appearing in most countries with a Jewish population by the 19th century. Along with Hebrew and Aramaic, it is one of the three major literary languages of Jewish history.
The earliest dated Yiddish documents are from the 12th century ce, but scholars have dated the origin of the language to the 9th century, when the Ashkenazim emerged as a unique cultural entity in central Europe. Yiddish first arose through an intricate fusion of two linguistic stocks: a Semitic component (containing postclassical Hebrew and Aramaic that the first settlers brought with them to Europe from the Middle East) and a grammatically and lexically more potent Germanic component (gleaned from a number of High German and Middle German dialects). In addition, a sprinkling of words from Romance languages also seems to have appeared in Yiddish from early on. From its birthplace on German-speaking soil, Yiddish spread to nearly all of eastern Europe, where the language acquired a Slavic component.
Western Yiddish, the only form of Yiddish that was used during the earliest history of the language, remained the dominant branch during the Old Yiddish period (ending about 1350). It comprises Southwestern (Swiss–Alsatian–Southern German), Midwestern (Central German), and Northwestern (Dutch–Northern German) Yiddish. Eastern Yiddish, roughly equal in importance to its western counterpart during the Middle Yiddish period (c. 1350–1600), vastly overtook it in the Early New Yiddish period (from roughly 1600) and includes all present-day spoken Yiddish. The major Eastern Yiddish dialects—Southeastern (spoken in Ukraine and Romania), Mideastern (Poland and Hungary), and Northeastern (Lithuania and Belarus)—form the basis of the modern standard pronunciation of Yiddish, though the grammar of the literary language draws from all three.
From its inception, Yiddish was the language of both the marketplace and the Talmudic academies. Yiddish literature continued to grow over the centuries, especially in genres not covered by traditional Hebrew and Aramaic. The rise of Yiddish printing in the 16th century stimulated the development of a standardized literary language on a Western Yiddish model. Owing to its gradual assimilation to German, as well as to a political campaign to stamp out the language waged by adherents of the late 18th-century Germanizing movement, Western Yiddish faded into eventual extinction.
By the early 19th century, Eastern Yiddish, by contrast, had blossomed; it became the basis for the new literary language. Prompted at first by Hasidism, a mystical movement of the 18th and 19th centuries, and spurred later by other social, educational, and political movements, Yiddish was carried to all the world’s continents by massive emigration from eastern Europe, extending its traditional role as the Jewish lingua franca. The Yiddishist movement, dedicated to the growth and enhancement of the language, was strengthened by the proliferation of Yiddish belles lettres. Its achievements include the Czernowitz Language Conference of 1908 (which proclaimed Yiddish a national Jewish language), the orthographic and linguistic reforms introduced by Ber Borokhov in 1913, and the founding of the Yiddish Scientific Institute (now YIVO Institute for Jewish Research) in Vilna (Vilnius), Lithuania, in 1925. YIVO has been headquartered in New York City since 1940.
Millions of Yiddish speakers were victims of the Nazi Holocaust. The number of speakers was further reduced by the official suppression of the language in the Soviet Union, by the antagonism of early Israeli authorities zealously guarding modern Hebrew, and by massive voluntary shifts to other primary languages in Western countries. The language nevertheless continues to flourish among the ultra-Orthodox Hasidim in numerous countries and among secular students of Yiddish at leading universities, including Columbia University (New York), Hebrew University (Jerusalem), McGill University (Montreal), the University of Oxford, and the University of Paris.