This was a British naval operation by Admiral Sir Andrew Cunningham’s Mediterranean fleet to provide gunfire support for 'Compass' (i), the first British land offensive in the Western Desert, in the area of Bardia near the eastern border of Italian Cyrenaica (2/4 January 1941).
A detachment of the Mediterranean Fleet departed Alexandria on 2 January with the fleet carrier Illustrious, escorted by the destroyers Greyhound, Griffin, Ilex and Juno, to fly on aircraft while at sea, the battleships Barham, Valiant and Warspite, the heavy cruiser York and the light cruiser Gloucester of the 3rd Cruiser Squadron, the light anti-aircraft cruiser Calcutta, and the destroyers Diamond, Gallant, Janus, Mohawk, Nubian, Wryneck and Australian Vendetta.
At first light on 3 January, the monitor Terror and the river gunboats Aphis, Gnat and Ladybird of Force 'W', escorted initially by the destroyers Dainty and Australian Voyager, completed a bombardment of the area to the north-west of Bardia, which they had been shelling since the previous day, in the process coming under three unsuccessful bombing and torpedo attacks which caused only slight bomb damage to Aphis with a near miss, and then pulled back to the north to clear the area for the heavier warships committed to 'MC5' proper. After 'MC5', the monitor and gunboats returned to their task before finally departing to Alexandria.
Greyhound, Griffin, Janus, Juno and Ilex then cleared the required firing lanes off Bardia using twin-speed destroyer minesweeping equipment.
Illustrious, York, Gloucester, Diamond, Gallant, Vendetta and Wryneck parted company with the Mediterranean Fleet to operate aircraft (Fairey Fulmar fighters of No. 806 Squadron and Fairey Swordfish anti-submarine aircraft of Nos 815 and 819 Squadrons) as necessary off shore, anti-aircraft protection being provided by Calcutta escorted by Mohawk and Nubian, joined by Dainty and Voyager after the latter two had been detached from Force 'W'.
Between 08.10 and 08.55 on 3 January, Barham, Valiant and Warspite, escorted by Greyhound, Griffin, Janus, Juno and Ilex, bombarded the areas to the north and east of Bardia, with spotting undertaken by the major ship’s Supermarine Walrus flying boats, to shield the British land forces' right flank. The battleships made two bombardment runs, one to the north and the other to the south, with their 15-in (381-mm) main guns tackling concentrations of armour and motor transport, and their lighter guns the Italian shore batteries, which responded but achieved no hit. The ships fired 246 rounds of 15-in (381-mm) ammunition and more than 500 rounds of 6- and 4.5-in (152- and 114-mm) ammunition, in the process completely discomfited the Italian garrison, which was overrun and surrendered to the advancing ground forces.
At 10.00 York, Gloucester and Calcutta were detached from the Mediterranean Fleet to return to Alexandria, while Vendetta and Wryneck were detached to steam to the south in the direction of Sollum just on the Egyptian side of the frontier.
The other ships returned to Alexandria on 4 January.