However, the Royal Navy had reverted to an earlier practice of naming the flotilla leader after a prominent historical seaman, in this case after Vice Admiral Sir Richard Grenville, an Elizabethan soldier and sailor.

[1] The U-class were War Emergency Programme destroyers, intended for general duties, including use as anti-submarine escort, and were to be suitable for mass-production.

615 tons of oil were carried, giving a range of 4,675 nautical miles (5,380 mi; 8,658 km) at 20 knots (23 mph; 37 km/h).

At the same time, the relatively recent War Emergency destroyers, with their low-angle guns and basic fire control systems, were considered unsuitable for modern warfare, so it was decided to convert these obsolete destroyers into fast escorts, acting as a stop-gap solution until new-build ships, such as the Type 12 frigates could be built in sufficient numbers.

[13][14] The revised ships had a much reduced gun armament of one twin 4-inch (102 mm) anti aircraft mount aft of the main superstructure and one twin Bofors mount, but anti-submarine equipment was as fitted to the Type 12s, with Grenville being fitted with two Limbo anti-submarine mortars, directed by Type 170 and 172 sonar.

[17] Later on, in September and October, Grenville was involved in a series of blockade runner sweeps along the French coast (Operation Tunnel).

Later in October, during another of these sweeps, Grenville was with the cruiser Charybdis and other destroyers in another, more disastrous, Operation Tunnel action against a blockade runner off the north coast of Brittany.

In the Mediterranean, she supported the Anzio landings, sunk an E-boat and destroyed a train near San Giorgio on the Adriatic Sea.

On 3 December, she was ordered to refuel, arriving immediately after the air raid on Bari, a mustard gas disaster.

Near the end of the Pacific war, several Allied warships began to relay Australian programmes to surrounding areas on shortwave.

In June 1966 she arrived back in Portsmouth under tow and was subsequently fitted with a third mast carrying experimental air-search radar, prior to its operational use in Invincible-class aircraft carriers.

In 1970 she was again present at Portsmouth Navy Days; at the time she was a trials ship for the Admiralty Surface Weapons Establishment (ASWE).