She spent most of World War II on convoy escort duties in the English Channel, and the North Atlantic, based at Dover, Gibraltar, and Freetown, Sierra Leone.

Brilliant carried a maximum of 390 long tons (400 t) of fuel oil that gave her a range of 4,800 nautical miles (8,900 km; 5,500 mi) at 15 knots (28 km/h; 17 mph).

[5] During a refit in March 1941, Brilliant's anti-aircraft armament was reinforced when the rear set of torpedo tubes was replaced by a 3-inch (76.2 mm) (12-pounder) AA gun and two 20-millimetre (0.8 in) Oerlikon autocannon were added.

She was laid down on 8 July 1929,[8] and launched on 9 October 1930, fully fitted out with armament, machinery and equipment, and ready to go to sea,[8][9] as the seventh RN ship to carry this name.

[12] On 31 December 1935, the Imperial Airways Short Calcutta flying boat City of Kharthoum crashed just outside the port of Alexandria, Egypt.

[12] On 24 August 1936, the flotilla leader Keith was in collision with the Greek steamer Atonis G. Lemos in thick fog 20 nautical miles (23 mi; 37 km) north of Alderney, sinking the merchant ship.

[14] During the winter of 1936–37, Brilliant enforced the arms blockade imposed by Britain and France on both sides by patrolling the Spanish ports on the Bay of Biscay.

[15][16] At the outbreak of war in September 1939, Brilliant was assigned to the 19th Destroyer Flotilla at Dover and spent the time before the Battle of France escorting convoys and minelaying operations.

On 15 May Brilliant collided with her sister ship Boreas en route for the Hook of Holland and was under repair at Sheerness Dockyard until 17 June.

On 12 May, Brilliant was sailed for Freetown, Sierra Leone where she served as a local escort and searched for German blockade runners and supply ships until returning home in April 1942 for a refit at Chatham.

Brilliant was able to rescue about 500 survivors from the damaged troopship, but due to various communication failures, no other vessels reached Leopoldville before she sank and 764 died.

This was completed on 26 May and Brilliant escorted the light cruiser Jamaica with King George VI aboard as he visited the Channel Islands on 7 June.

From 13 June, based at Holy Loch, Scotland, she escorted surrendered U-boats as part of Operation Deadlight before being paid off into reserve in November 1945.

Brilliant was allocated to the Target Trials Committee on 11 September[6] and was used evaluate the shock effects of a 1,090-pound (490 kg) underwater explosion in April 1947.