(also Russkaia Zemlia, literally “Russian land”), the name of the state created by the eastern Slavs in the middle Dnieper region in the ninth and tenth centuries A.D. The existence of this state is confirmed by Constantine Porphyrogenitus in his De administrando imperio (tenth century), by the tenth-century treaties between Rus’ and Byzantium, and by Russian chronicles of the 11th and 12th centuries.

The major cities of Rus’ were Kiev, Chernigov, and Pereiaslavl’ (Iuzhnyi). Later Russian chronicles make it possible to define the territorial boundaries of Rus’ more precisely. According to sources of the 11th and 12th centuries, Rus’ included not only Kiev, Chernigov, and Pereiaslavl’ but also Vyshgorod, Belgorod, Torchesk, Trepol’, Boguslavl’, Korsun’, Kanev, Shumsk, Tikhoml’, Vygoshev, Gnoinitsa, and Buzhsk. All these cities were in what had once been the tribal lands of the Poliane, part of the lands of the Severiane and the Radimichi, and perhaps certain lands of the Ulichi and Viatichi. As its territorial extent indicates, Rus’ was neither a tribal nor an ethnic formation but a political one.

The formation of classes in Rus’ and adjacent lands inhabited by eastern Slavic tribes and the growth of a local elite led to the formation of the ancient Russian state (seeKIEVAN RUS’), named Rus’ after its original nucleus.

At the beginning of the 12th century, the term Russkaia Zemlia already referred not only to the territory of ancient Rus’ but also to all the Slavic tribes of Eastern Europe. It is used in this historico-geographical sense in the Primary Chronicle: “This is the tale of bygone years, telling whence came the Russian Land.” At the beginning of the 13th century, the terms Rus’ and Russkaia Zemlia came to denote the northeastern areas of the ancient Russian state—that is, the Rostov-Suzdal’ and Novgorod lands. After the Mongol conquest of 1237–41, the term Rus’ customarily referred to these areas, although in 13th- and 14th-century sources it also had a much broader meaning, which included all the areas inhabited by the eastern Slavs. In the 13th century and later, when the ties between the various areas of the ancient Russian state were seriously weakened, new terms came into use, namely, Belaia Rus’, Malaia Rus’, and Chernaia Rus’. These new names referred to distinct territories, each with its own historical fate. The terms “Russian” and “Russians” are derived from Rus’.