The "seventy-four" was a type of two-decked sailing ship of the line nominally carrying 74 guns. Originally developed by the French Navy in the mid-18th century, the design proved to be a good balance between firepower and sailing qualities, and was adopted by the British Royal Navy (where the ships were classed as third rates), as well as other navies. Seventy-fours were a mainstay of the world's fleets into the early decades of the 19th century, when they were supplanted by improved construction techniques allowing larger vessels and by the introduction of steam power.