Аннотация:Chuvash is the sole living representative of the Bulgharic branch, one of the two principal branches of the Turkic family. While extinct Bulgharic varieties are only limitedly accessible to linguists owing to the scarcity of written sources, Chuvash has attracted a lot of attention as the most divergent Turkic language, notable for both archaic features and innovations against the background of the Common Turkic branch. For a century, because of its salient features, Chuvash has played a key role in the Altaic and, further, Transeurasian debate. This chapter provides a historical overview and a grammar sketch of Chuvash as seen from both a genealogical and an areal perspective. As shown in the chapter, Chuvash exhibits numerous features that are typical of Transeurasian languages in general and Turkic in particular. At the same time, some other traits that can be found in modern Chuvash may have been adopted through contact with non-Transeurasian languages, most notably Uralic, such as Mari, and Indo-European, such as Russian.