Battleship

A battleship is a large, heavily armored warship with a main battery consisting of large guns, designed to serve as capital ships. From their advent in the late 1880s, battleships were among the largest and most formidable weapon systems ever built, until they were surpassed by aircraft carriers beginning in the 1940s. The modern battleship traces its origin to the sailing ship of the line, which was developed into the steam ship of the line and soon thereafter the ironclad warship. After a period of extensive experimentation in the 1870s and 1880s, ironclad design was largely standardized by the British Royal Sovereign class, which are usually referred to as the first "pre-dreadnought battleships". These ships carried an armament that usually included four large guns and several medium-caliber guns that were to be used against enemy battleships, and numerous small guns for self defense.

Naval powers around the world built dozens of pre-dreadnoughts in the 1890s and early 1900s, though they saw relatively little combat; only two major wars were fought during the period that included pre-dreadnought battles: the Spanish-American War in 1898 and the Russo-Japanese War of 1904–1905. The following year, the British launched the revolutionary all-big-gun battleship HMS Dreadnought. This ship discarded the medium-caliber guns in exchange for a uniform armament of ten large guns. All other major navies quickly began (or had already started) "dreadnoughts" of their own, leading to a major naval arms race. During World War I, only one major fleet engagement took place: the Battle of Jutland in 1916, but neither side was able to achieve a decisive result.

In the Interwar period, the major naval powers concluded a series of agreements beginning with the Washington Naval Treaty that imposed limits on battleship building to stop a renewed arms race. During this period, relatively few battleships were built, but advances in technology led to the maturation of the fast battleship concept, and several of these ships were built in the 1930s. The treaty system eventually broke down after Japan refused to sign the Second London Naval Treaty in 1936. Although the rise of the aircraft carrier during World War II largely relegated battleships to secondary duties, they still saw significant action during that conflict. Notable engagements include the battles of Cape Spartivento and Cape Matapan in 1940 and 1941, respectively; the sortie by the German battleship Bismarck in 1941; the Naval Battle of Guadalcanal in 1942; and the Battle of Leyte Gulf in 1944. After World War II, most battleships were placed in reserve, broken up, or used as target ships, and few saw significant active service during the Cold War. The four American Iowa-class battleships were reactivated during the Korean War in the early 1950s and again in the 1980s as part of the 600-ship Navy.

Even at the height of their dominance of naval combat, some strategists questioned the usefulness of battleships. Beginning in the mid-1880s, the Jeune École (Young School) argued that construction of expensive capital ships should stop in favor of cheap cruisers and torpedo boats. Despite a period of popularity for the Jeune École, the idea fell out of favor and the battleship remained the arbiter of naval combat until World War II. Even afterward, they remained potent symbols of a country's might and they retained significant psychological and diplomatic effects. A number of battleships—predominantly American—remain as museum ships.