Renaissance era ranged naval unit.

Over the centuries the frigate has evolved from a square-rigged three-master in the 1700s too small to stand in the line-of-battle to the fast guided-missile toting warship, nimble enough to avoid the really big ships. But the role of the frigate in naval warfare hasn’t changed: patrol and/or escort duties. The British Royal Navy declared a frigate to be any full-rigged “rated ship” carrying at least 28 guns on a single continuous deck; but despite the Admiralty’s best efforts to define a “frigate,” these came in all sizes and configurations, even ironclads by the mid-1800s. Modern “frigates” are frigates in name only; commencing with WW2, the label was applied to anything smaller than a destroyer. The introduction of missiles to modern naval warfare made frigates even more lethal, and cost-effective. Why build a blundering great battleship, or even a cruiser or destroyer, when a “cheap” frigate would do?