In the 10th century, the lands of the Crimean Goths were once again raided by the Khazars. As a response, the leaders of the Crimean Goths made an alliance with Sviatoslav I of Kiev, who subsequently waged war upon and utterly destroyed the Khazar Khaganate. In the late Middle Ages the Crimean Goths were part of the Principality of Theodoro, which was conquered by the Ottoman Empire in the late 15th century. As late as the 18th century a small number of people in Crimea may still have spoken Crimean Gothic.