In the 15th century, Pokuttya, the region immediately to the north, became the subject of disputes between the Principality of Moldavia and the Polish Kingdom. Pokuttya was likewise inhabited by Ruthenians (the predecessors of modern Ukrainians together with the Rus', and of the Rusyns). Further there were the Hutsuls, who also resided in western Bukovina. In 1497 a battle took place at the Cosmin Forest (the hilly forests separating Chernivtsi and Siret valleys), at which Stephen III of Moldavia (Stephen the Great), managed to defeat the much-stronger but demoralized army of King John I Albert of Poland. The battle is known in Polish popular culture as "the battle when the Knights have perished". The region had been under Polish nominal dominion from its foundation (1387) to the time of this battle (1497). Shortly thereafter, it became a vassal of the Ottoman Empire (1514).