These are the latest class of Frigates to enter service in the Royal Navy. The Type 23 frigates were originally designed as cheap replacements for the Leander class frigates. However their design altered quite radically as a result from lessons learnt as a result of the Falkland's War.

One of the principal differences between the Type 23 and its predecessor the Type 22 (with the exception of the Type 22 (batch 3) ships) is the re-introduction of the gun. It had been thought that the days of needing a gun on a Royal Naval vessel were gone. However the Falkland's War showed that the gun remains a necessary part of Naval warfare. The Royal Navy, however, adopted a sensible approach when deciding to re-introduce the gun, and rather than introduce a cumbersome 6 inch gun with a reasonably slow firing rate, they settled on a 4.5 inch gun with a high firing rate. Indeed the gun is capable of firing up to 25 rpm at a range of 22km. Another feature of the Type 23 designed as a result of the Falkland's war is a reduced radar signature profile.

HMS NORFOLK was the first Type 23 to enter service in the Royal Navy, she was commissioned on 1st June 1990. The Type 23s are general purpose frigates and so although capable of ASW and air-defence, they are similarly capable of independent action when required. The type 23s have frequently been dispatched to the Gulf where they operate independently in stopping and searching merchant vessels. Along with the Harpoon SSM, the Lynx or Merlin helicopters are capable of providing ASV capability. The modern Lynx and the Merlin (which has recently entered service) are highly advanced aircraft which are more than capable of fulfilling the roles assigned to them. The combination of the Lynx/Merlin with a Type 23 ensures that the Type 23s are one of the most capable units in the world.

The Type 23s are the first Royal Naval vessels to carry the VL Sea Wolf system. Seawolf is an anti-aircraft and anti-missile system. It is highly potent, with a closing speed in excess of Mach 2. The advantage of the VL Sea Wolf is that there are no blind spots: one of the problems with the launcher-mounted Sea Wolves is that the launcher is not capable of firing throughout 360 degrees because the ship's superstructure would get in the way. The VL Sea Wolf is launched vertically via a booster which detatches automatically once clear of the superstructure. The missile then turns towards the target.

In modern naval warfare stealth is a big advantage. It was noted above that the Type 23 has a reduced radar signature profile, and its main propulsion system (CODLAG) permits it to run nearly silent at times. This has major advantages in ASW where noise can be one of the great disadvantages as it permits the submarine to locate the surface vessel using only passive sonar.