With over half her massive landmass bordered by water, Russia's navywas (and still is today) divided into four major fleets: the Pacific, Northern, Baltic and Black Sea Fleets; at the height of the Russian Empire, the Imperial Russian Navy was the fourth most powerful fleet in the world after Great Britain, Spain and France. Lagging technological advancement and disastrous wars greatly dented her power, resulting in mixed performance in World War I; the Northern Fleet was created during the War to protect shipping in the Barents Sea, the Baltic Fleet played a largely defensive role, the Black Sea Fleet distinguished herself against the Ottoman Navy and the Pacific Fleet had faded into insignificance following the Russo-Japanese War and the Battle of Tsushima in 1905. The Imperial Russian Navy suffered a near-complete collapse in the Russian Revolution and the resulting Civil War during the closing years of World War I, and was eventually succeeded by the Soviet Union's Red Fleet.
In the years between the World Wars, the rapidly-industrializing Soviet Union (or U.S.S.R.) planned to rebuild the navy, but the Great Purge prevented any meaningful progress, and the Red Fleet would only have a handful of cruisers, obsolete battleships and a reasonable number of destroyers when the U.S.S.R. entered World War II in June 1941 with Germany's invasion of the Soviet Union, Operation Barbarossa. However, this did not stop the Red Fleet from performing with distinction: the Baltic Fleet used its sizable submarine fleet to great effect against the Kriegsmarine and the Finnish Navy despite suffering terrible losses themselves; the Naval Aviation service, while not having a single aircraft carrier, sank more ships and crew than any other unit; Russian resourcefulness and tenacity was exemplified by naval guns still being put to use even after extensive damage to individual ships (such as battleship Marat). Thousands of sailors and naval equipment were drafted to reinforce the Red Army as needed, fighting with incredible valor in many significant engagements, including the Battles of Odessa, Sevastopol, Stalingrad, Novorossiysk, and Leningrad. After World War II, the Red Fleet was renamed the Soviet Navy, and went on to play a major role in the Cold War with the United States.