The Dnieper, also called Dnipro or Dniapro, is one of the major transboundary rivers of Europe, rising in the Valdai Hills near Smolensk, Russia, before flowing through Belarus and Ukraine to the Black Sea. Approximately 2,200 km (1,400 mi) long, with a drainage basin of 504,000 square kilometres (195,000 sq mi), it is the longest river of Ukraine and Belarus and the fourth-longest river in Europe, after the Volga, Danube, and Ural rivers.

The Tsardom of Russia, also known as the Tsardom of Muscovy, was the centralized Russian state from the assumption of the title of tsar by Ivan IV in 1547 until the foundation of the Russian Empire by Peter the Great in 1721.