The Type 23 or Duke class frigate was built for the Royal Navy and first entered service in 1989. The ships are named after British Dukes. The first Type 23, HMS Norfolk was commissioned in 1989, and the sixteenth, HMS St Albans in June 2002. They form the backbone of the Royal Navy's escort fleet and serve alongside the Type 45 destroyers. Originally designed for anti-submarine warfare in the North Atlantic they have proven their versatility again and again around the globe. Thirteen Type 23 frigates remain in service with the Royal Navy, with three vessels having been sold to Chile.
They are heavily armed with a 4.5 gun,anti-air and anti-ship missiles and a Merlin anti-submarine helicopter.