Why do Chuvashes living next to Mari in middle Volga speak Oghur? aWe know for a fact from numerous sources about the existence of Volga Bulgaria in this region – confluence of Volga and Kama river near present day Mari El and Tatarstan Republic between 7th-13th centuries before Mongol invasion. Map of Chuvash republic. Yoshkar Ola is capital of Finno-Ugric speaking Mari, who genetically and culturally related to Chuvashes except the language.
There was no Turkic living in the regtion prior to the arrival of Bulgars.