navy, originally, all ships of a nation, whether for war or commerce; the term navy now designates only such vessels as are built and maintained specifically for war. There have been three major developments in naval vessels. From ancient times to the late 16th cent., navies consisted mostly of galleys; from the late 16th to the late 19th cent., they consisted mostly of side-gunned sailing vessels; and from 1865 until recently, they consisted of steam warships. Currently, diesel-powered ships dominate the world's navies, although many ships are nuclear-powered.
Navies began in the Mediterranean, with its access to three continents and favorable climatic conditions. Although the first recorded naval battle was c.1200 BC between the Egyptians and the Sea People, ships were probably used to transport and supply armies much earlier. Ancient warships usually relied on ramming, although sometimes catapults were used to fire missiles or incendiaries, and their crews fought as infantry. Galleys dominated the Mediterranean at least through the battle of Lepanto (1571) between the Christians and Muslims. In China, junks (high-pooped ships with battened sails) were used as fighting platforms for sea battles and for invasion fleets, such as the Mongol attempt to take Japan in 1281. In northern Europe the Norse perfected oared Viking ships with square sails and strong keels that were used to transport raiders or for boarding at sea, but they could not ram or carry as many fighters as a galley. They were organized into small but effective fleets. It was to meet their attacks that Alfred the Great, in the 9th cent., organized a royal fleet and became the first to realize that a navy was essential to England's security.
The reigns of Henry VIII and Elizabeth saw further naval developments. Between the 13th and 16th cent. the commercial trading vessels of Northern Europe evolved into effective warships, with rudders, keels, and complex sails. They soon became dominant around the world because of their increased maneuverability, their load-carrying capacity, and their suitability for carrying cannon. The Spanish and Portuguese navies dominated at different times until the destruction of the Spanish Armada (1588). From then on the British navy was the strongest in the world. Although challenged often, first by the Dutch and then the French, it ruled the seas for 300 years. British naval power rested not so much on numbers or superior ship construction, but on its professional seamen and officers. While Britain remained dominant, Germany, Italy, Japan, and the United States developed strong navies.
In the late 19th cent., the emergence of Japan and Germany as major naval powers encouraged the United States to establish a strong navy. In 1898, the United States destroyed the Spanish fleet in the Spanish-American War and emerged as the second strongest sea power in the world. At this time, such modern naval weapons as the torpedo, the rifled naval gun, and the submarine were developed. World War I was partially a contest between the naval strengths of Britain and Germany, with the submarine the crucial factor. Germany lost its navy at the end of the war.
After World War I naval tactics were revolutionized by the development of the airplane. Previously, the decisive naval weapons had been the heavily gunned cruisers and battleships. In World War II, it became the aircraft carrier, as proven when U.S. carrier-based aircraft dominated the Pacific and did much to cripple German submarine strength in the Atlantic. At the end of World War II, Germany, Italy, and Japan were stripped of their navies, Britain was economically weakened, and the United States emerged with the strongest navy in the world. By the early 1970s the USSR (now Russia) had the second most powerful navy; it was weakened, however, by the collapse of the USSR (1991) and Russia's subsequent economic difficulties. The development of nuclear-powered vessels, especially the submarine, together with nuclear weaponry, has altered the role of the navy in a nation's strategy and tactics.
See A. T. Mahan, The Influence of Sea Power upon History (1890); B. Brodie Naval Strategy (1942); H. T. Lenton, Warships of the British and Commonwealth Navies (1966); L. W. Martin, The Sea in Modern Strategy (1967); F. Pratt and H. E. Howe, Compact History of the United States Navy (rev. ed. 1967); P. Padfield, Guns at Sea (1973); C. Reynolds, Command of the Sea (1974); J. Guilmartin, Galleys and Gunpowder (1975); N. A. M. Rodgers, The Wooden World (1986); R. H. Spector, At War at Sea: Sailors and Naval Combat in the Twentieth Century (2001); I. W. Toll, Six Frigates: The Epic History of the Founding of the U.S. Navy (2006).