A corvette is a small, manoeuverable, lightly armed warship, originally smaller than a frigate and larger than a coastal patrol craft, although many recent designs resemble frigates in size and role. During the Age of Sail, corvettes were smaller than frigates and larger than sloops-of-war, usually with a single gun deck. Almost all modern navies use ships smaller than frigates for coastal duty, not all of them use the term corvette (from the French corvair) or equivalent. The rank Corvette Captain derives from the name of this type of ship.

Sailing vessels

During the Age of Sail, corvettes were one of many types of smaller warships. They were very closely related to sloops-of-war. The role of the corvette consisted mostly of coastal patrol, fighting minor wars, supporting large fleets, or participating in show-the-flag missions. The British Navy began using small ships in the 1650s, but described them as sloops rather than corvettes. The first reference to a corvette was with the French Navy in the 1670s, which is where the term itself possibly originated. The Royal Navy did not use the term until after the Napoleonic Wars to describe a small un-rated vessel similar to a sloop.

Most corvettes and sloops of the 17th century were around 40 to 60 feet (12 to 18 meters) in length and weighed 40 to 70 short tons (35 to 65 metric tonnes). They carried four to eight smaller guns on a single deck. Over time vessels of increasing size and capability were called corvettes; by 1800 they reached lengths of over 100 feet (30 m) and weights ranging from 400 to 600 short tons (around 360 to 540 metric tonnes). One of the largest corvettes during the Age of Sail was the American ship USS Constellation, built in 1855; at 176 feet (54 m) long, she carried 24 guns. She was so large that some naval experts consider her a frigate, or a sloop-of-war.

Steam ships

Ships during the steam era became much faster and more maneuverable than their sail ancestors. Corvettes during this era were typically used alongside gunboats during colonial missions. Battleships and other large vessels were unnecessary when fighting the indigenous people of the Far East and Africa.

World War II

The modern corvette appeared during World War II as an easily built patrol and convoy escort vessel. The British naval designer William Reed drew up a small ship based on the single-shaft Smiths Dock Company whale catcher Southern Pride, whose simple design and mercantile construction standards lent itself to rapid production in small yards unused to naval work, and in large numbers. First Lord of the Admiralty Winston Churchill, later Prime Minister, had a hand in reviving the name "corvette".