Dnieper (nēˈpər) [key], Rus. Dnepr, Ukr. Dnipro, river, c.1,430 mi (2,300 km) long, in Russia, Belarus, and Ukraine. One of the longest rivers in Europe, it rises in the Valdai Hills, W of Moscow. It flows generally S past Smolensk, through Belarus, past Mogilev, then through Ukraine, past Kiev, Cherkasy, Kremenchuk, Dnipropetrovsk, Zaporizhzhya (site of the Dniprohes dam), Nikopol, and Kherson into the Black Sea. Between Kremenchuk and Nikopol the Dnieper makes a vast bend to the east. It is the main river of Ukraine. Since the construction (1932) of the Dniprohes dam the Dnieper is navigable for virtually its entire course. Its tributaries include the Berezina, the Pripyat, and the Inhulets from the west and the Sozh, the Desna, the Orel, and the Samara from the east. The Dnieper is linked by canal with the Western Bug. Known as Borysthenes to the ancients, the river was (9th–11th cent.) a commercial route for the Vikings, Slavs, and Byzantines.