At least three Arabic-speaking 10th century geographers who traveled the area mention the city of Zānbat as the chief city of the Russes.  Among them are Ahmad ibn Rustah, Abu Sa'id Gardezi, and an author of the Hudud al-'Alam. The texts of those authors were discovered by Russian orientalist Alexander Tumansky. The etymology of Sambat has been argued by many historians, including Grigoriy Ilyinsky, Nikolay Karamzin, Jan Potocki, Nikolay Lambin, Joachim Lelewel, Guðbrandur Vigfússon. The historian Julius Brutzkus in his work "The Khazar Origin of Ancient Kiev" hypothesizes that both Sambat and Kyiv are of Khazar origin meaning "hill fortress" and "lower settlement" respectively. Brutzkus claims that Sambat is not Kyiv, but rather Vyshhorod (High City) which is located nearby.