lineofbattle

Line of battle is a naval term describing a formation and tactic used from the 17th to the mid-19th century in which a fleet deployed in a single line of ships from one flank to the other to maximize the effectiveness of its broadsides. The vessels involved were known as ships of the line, and they were the largest warships in a navy, rated by firepower (for example, first-rate, second-rate, etc.). The primary aim of the line was to present the strongest broadside to the enemy while keeping ships in mutual support and maintaining the ability to maneuver with the wind.

In practice, fleets formed a line ahead or line of bearing so each ship could fire to its broadside without risking the exposed stern or bow of neighboring ships. The tactic required disciplined seamanship, precise signaling, and favorable sailing conditions, as wind, currents, and weather could easily disrupt the line. Battles were often decided by the careful handling of maneuver and the range at which ships could safely open fire, with lines advancing or retreating in steps and engaging along the length of the formation.

The line of battle era saw its most famous engagements during the Age of Sail, such as Trafalgar and other large fleet actions, where the concentration of firepower and orderly maneuver proved decisive. The approach declined with the rise of steam propulsion, armored ships, and changes in naval doctrine in the mid-to-late 19th century, which introduced new formations and tactics. Today, the phrase remains primarily historical, used to describe the traditional fleet arrangement and its related battles.