A battleship is a large, heavily armored warship with a main battery consisting of the largest calibre of guns. Battleships were larger, better armed, and better armored than cruisers and destroyers.

Battleship design continually evolved to incorporate and adapt technological advances to maintain an edge. The word battleship was coined around 1794 and is a shortened form of line-of-battle ship, the dominant wooden warship during the Age of Sail."battleship" The Oxford English Dictionary. 2nd ed. 1989. OED Online. Oxford University Press. 4 April 2000 The term came into formal use in the late 1880s to describe a type of ironclad warship,Stoll, J. Steaming in the Dark?, Journal of Conflict Resolution Vol. 36 No. 2, Jun 1992 now referred to as pre-dreadnought battleships. In 1906, the launch of HMS Dreadnought heralded a revolution in battleship design, and subsequent types were referred to as dreadnoughts.

Battleships were a potent symbol of naval dominance and national might, and for decades the battleship was a major factor in both diplomacy and military strategy.Sondhaus, L. Naval Warfare 1815–1914, ISBN 0-415-21478-5 The global arms race in battleship construction in the early 20th century was one of the causes of World War I, which saw a clash of huge battle fleets at the Battle of Jutland. The Naval Treaties of the 1920s and 1930s limited the number of battleships but did not end the evolution of design. Both the Allies and the Axis Powers deployed battleships of old construction and new during World War II.

Nevertheless, some historians and naval theorists question the value of the battleship. The Battle of Tsushima (1905) was the only decisive clash between steel battleship fleets, and apart from the indecisive Battle of Jutland (1916), there were few great battleship clashes. Despite their great firepower and protection, battleships were increasingly vulnerable to much smaller, cheaper ordnance and craft: initially the torpedo and the naval mine, and later aircraft and the guided missile.Lenton, H. T.: Krigsfartyg efter 1860 The growing range of naval engagement led to the aircraft carrier replacing the battleship as the leading capital ship during World War II. Battleships were retained by the United States Navy into the Cold War only for fire support purposes. The last battleships were removed from the U.S. Naval Vessel Register in March 2006.

Ships of the line

main: Ship of the line A ship of the line was a large, unarmoured wooden sailing ship on which was mounted a battery of up to 120 smoothbore guns and carronades. The ship of the line was a gradual evolution of a basic design that dates back to the 1400s, and, apart from growing in size, it changed little between the adoption of line of battle tactics in the early 17th century and the end of the sailing battleship's heyday in the 1830s. From 1794, the alternative term 'line of battle ship' was contracted (informally at first) to 'battle ship' or 'battleship'.