The Salisbury class frigates were conceived as part of the 1944 project for common-hull diesel-powered 1700-ton anti-submarine (A/S), air-warfare (AW) and aircraft direction (AD) vessels.

[6] The design of the new air defence frigates could proceed faster as the requirements were clearer and less complex and fuel-efficient diesel power was adequate for convoy escort picket ships.

However the design of efficient powerful steam turbines for affordable common hulled anti-sub frigates with the range to escort Atlantic convoys and speed to screen carrier task forces took years and was never entirely achieved.

Neither the Dido-class cruisers nor the Daring-class destroyers had the space required to combine the processing of radar and communications with dual-purpose AA guns.

This integration was complicated, making the new diesel air warning and aircraft direction frigates an even higher priority.

The AD cruisers were used in Operation Musketeer during the 1056 Suez Crisis; Hawker Sea Hawk ground attack and English Electric Canberra and Vickers Valiant bomber aircraft struck land air bases and other targets.

HMS Jaguar (a Type 41) and Lincoln were refitted as specialised rammers with a reinforced bow to present a higher-level threat to Icelandic gunboats.

With the expanded 200 mile offshore zones, partly stemming from the Cod Wars, Lincoln remained in commission to late 1977 on deep water patrol.

The Type 986 radar was intended to partially replace one of the roles of 984, giving more accurate, short-range definition of closing air targets to 120 kilometres (75 mi).

It was only a partial replacement, as it lacked the 984 system's ability to rank and prioritize large numbers of targets for interrogation and air interception.

HMS Salisbury, under the first frigate command of Hugo White (later Admiral of the Fleet), was extensively involved in the third Cod War, holding the line against Icelandic gunboats within 4.8 kilometres (3 mi) of multinational fishing fleets, colliding seven times with the Iceland gunboats Tyr and Aegir in March and April 1976.