The "seventy-four" was a type of two-decked sailing ship of the line, which nominally carried 74 guns.

Impressed with the performance of several captured French seventy-fours, the British Royal Navy quickly adopted similar designs, classing them as third rates.

[1] The first 74-gun ships were constructed by the French as they rebuilt their navy during the early years of the reign of Louis XV.

[3] This was copied by the Royal Navy in about two dozen such ships of its own, such as HMS Colossus where they were known as Large, while the other seventy-fours built to be between 166–171 feet (51–52 m) were known as Common.

[4] The significance of the 74s however is hard to overstate, as shown by a summary of the ships of the line for all nations that were in commission at any time during the Revolutionary/Napoleonic Wars period.

This limited the success of the even bigger two-deck 80-gun ships that were built in small numbers after the seventy-four had been introduced.

The Royal Navy captured a number of the early French 74-gun ships during the War of the Austrian Succession (for example, Invincible, captured at the first battle of Cape Finisterre in 1747) and the Seven Years' War and was greatly impressed by them compared to its own smallish 70-gun ships.