According to Ukrainian historian Vitaliy Shcherbak the term appeared sometime in the 15th century for territory between the Dniester and mid-Volga when colonization of the region by Cossacks started.[2] Shcherbak notes that the term's contemporaries, such as Michalo Lituanus [lt; ru],[3][4] Blaise de Vigenère, and Józef Wereszczyński [pl; ru],[5] wrote about the unseen[clarification needed] natural riches of the steppes and the Dnieper basin.[2]