" The ancestors of modern Ukrainians lived in dozens of premodern and modern principalities, kingdoms, and empires, and in the course of time they took on various names and identities. The two key terms that they used to define their land were “Rus’” and “Ukraine.” (In the Cyrillic alphabet, Rus’ is spelled Pycь: the last character is a soft sign indicating palatalized pronunciation of the preceding consonant.) The term “Rus’,” brought to the region by the Vikings in the ninth and tenth centuries, was adopted by the inhabitants of Kyivan Rus’, who took the Viking princes and warriors into their fold and Slavicized them. The ancestors of today’s Ukrainians, Russians, and Belarusians adopted the name “Rus’” in forms that varied from the Scandinavian/Slavic “Rus’” to the Hellenized “Rossiia.” In the eighteenth century, Muscovy adopted the latter form as the official name of its state and empire. "

― Serhii Plokhy , The Gates of Europe: A History of Ukraine