The Rothesay-class was an improved version of the Whitby-class anti-submarine frigate, with nine Rothesays ordered in the 1954–55 shipbuilding programme for the Royal Navy to supplement the six Whitbys.

Seacat was not yet ready, and Rothesay was completed with a twin Mark 5 L/60 40 mm Bofors mount aft as a temporary anti-aircraft armament.

[10][11] From 1966 to 1968 Rothesay underwent a major modernisation, which brought the ship close in capacity to the Leander class.

On 21 March 1962 she accidentally rammed the Turkish Balao-class submarine TCG Gür in the western Mediterranean (off Gibraltar) during the NATO exercise "Dawn Breeze".

[citation needed][16] On 14/15 January 1966 Rothesay rescued 134 Haitian refugees, who had been attempting to reach the Bahamas in a 35-foot (11 m) long fishing boat but had run aground on an uninhabited island.

On 19 March 1969, together with Minerva, they landed 315 men of The Parachute Regiment on Anguilla to restore order after the islanders objected to being placed under the government of Saint Kitts.

[18] In April 1970 Rothesay was one of several Royal Navy vessels that were stationed for a possible tertiary splashdown recovery of Apollo 13 in a position just south of Rio de Janeiro, Brazil.

[20] At the start of the Falklands War, Rothesay was in Rosyth under repair after she hit a sea wall in Esbjerg, Denmark.

There were plans to withdraw the ship from service in 1983, but these were abandoned and instead in 1985 she underwent a refit in preparation for her new role in the Dartmouth Training Squadron.