|The post-World War II Royal Navy looked towards specialization in its ship construction plans, veering away from the all-purpose fleet destroyer to a new style of frigate. During World War II, the term frigate was used to identify an escort vessel that
was, in terms of size, between a smaller corvette and a larger destroyer. However, the new frigate envisioned during the 1950s was a much larger vessel than their World War II cousins and comparable to a destroyer in terms of speed and
displacement. The new frigates all had similar hulls, with a high foc’sle deck which sloped down to the gun deck just forward of the bridge. However, the ships varied in armament depending on the specialized duties they would perform: anti-aircraft
(A/A), anti-submarine (A/S) and aircraft direction (A/D). The one armament common to all frigates was the enclosed twin 4.5-inch turret. Eventually it became clear that specialization was costly, especially in terms of maintenance and re-equipment,
and a decision was made to develop a General Purpose (GP) design that could perform all three functions. The first GP design was the Type 81 or Tribal class frigate and while there some limitations to this class, the GP concept proved to be a better
The Leander class reverted back to the high foc’sle hull of the previous specialized frigates (the Tribals had a more traditional forward hull) and were to be named after mythological characters, with the exception of Cleopatra, who was a historical
figure. The first three ships in the class, Leander, Ajax and Dido, were laid down as Rothesay class (Type 12M) frigates but now the ships were to incorporate all of the attributes of the specialized predecessors – a Type 965 “bedstead” early warning
radar, twin 4.5-inch gun turret, triple-barreled Limbo A/S mortar, Wasp A/S helicopter, Seacat guided missile weapon system and variable depth sonar. Largely for this reason, the Leanders were classified as Type 12I for Improved.