Dnieper (nē′ pẽr), a river of Russia and the most important river of Europe, next to the Volga and the Danube. It rises at the foot of Voldai Hills, in the government of Smolensk, flows south to Kiev, and finally into the Black Sea. It is about 1,200 miles long, and has several large tributaries, all of which are navigable; but, owing to many natural obstructions, it is not so important for commerce as it otherwise would be. The Russian government has greatly improved the course of the river by taking away many of the obstructions and by building canals around some of the cataracts. Canals connect the Dnieper by means of its tributaries with the Duna of Niemen and Bog, and thus join the Black and Baltic Seas. It passes through the richest provinces of Russia, and at Smolensk is covered with ice from November to April. There is a fine suspension bridge, half a mile long, at Kiev. The river was anciently known as the Borysthenes, and was thought to be the largest river in the world, except the Nile.