to the region between rivers inhabited by the early Hungarians. Although the word does not survive in modern Hungarian, comparable hydronyms are attested elsewhere, such as the name of the White River (Ak Adil) in Bashkiria, and the ancestors of the Bashkirs spoke a Ugric language that was understandable to Hungarians as early as the 13th century.

A number of Islamic sources in particular Ibn Khordadbeh,