'MC2' and 'MC3' were a British pair of closely related naval undertakings within 'Hide' by Admiral Sir Andrew Cunningham’s Mediterranean Fleet after the arrival of the ME.4 convoy (16/24 November 1940).
The operation had five objectives, namely the passages of the MW.5A convoy (9,816-ton British Lanarkshire and 12,435-ton British Waiwera) from Alexandria to Malta and MW.5B convoy (6,054-ton British Devis, 9,351-ton Norwegian Hoegh Wood, 8,319-ton British Pontfield, 3,338-ton British Rodi and 1,587-ton British Volo) from Port Said to Malta; of the battleship Malaya, four destroyers and the MG.1 convoy (7,529-ton British Clan Forbes and 7,529-ton British Clan Fraser) from Alexandria or Malta to Gibraltar (16/24 December 1940); of the ME.5A eastbound convoy (7,347-ton British Clan Ferguson, 10,492-ton British Clan Macaulay, 9,776-ton British commissioned Breconshire, and 7,506-ton British Memnon) from Malta to Alexandria; of the AS.9 convoy (3,359-ton Dutch Adinda, Argo, 5,917-ton British fleet oiler Brambleleaf, British Frinton, 1,579-ton Greek Hollandia, 4,476-ton Greek Hydraios, 4,038-ton British Jhelum, 1,968-ton Greek Kehrea, tanker Petroil and Prodromos) from Piraeus to Alexandria; and of the 3,791-ton commissioned transport Ulster Prince with troops to Crete and Greece.
On 16 December the battleship Malaya and the destroyers Defender and Diamond began the close escort of the MW.5 convoys of seven merchant vessels from Alexandria to Malta, with more distant cover provided by another two of the Mediterranean Fleet’s battleships, Valiant and Warspite, the fleet carrier Illustrious, the heavy cruiser York, light the cruiser Gloucester, and the destroyers Dainty, Greyhound, Hasty, Hereward, Hero, Hyperion, Ilex, Janus, Jervis, Juno and Mohawk, which departed Alexandria at 01.00 on 16 December in 'MC2'.
For a short time the cruisers were detached to operate in the Aegean Sea against Italian targets in the Dodecanese islands group, and Illustrious launched 11 Fairey Swordfish aircraft on 17 December as six to attack airfields on Italian-occupied Rhodes and five to attack Stampalia (Astypálaia in Greek).
During the night of 18/19 December Warspite and Valiant were detached to shell the ports of Skala and Valona in Italian-occupied Albania, the battleships being escorted by the destroyers Hasty, Hereward, Hero, Hyperion, Ilex and Mohawk. At the same time Rear Admiral H. D. Pridham-Wippell led his 7th Cruiser Squadron (light cruisers Ajax, Orion and Australian Sydney), supported by the destroyers Janus, Jervis and Juno, toward the Strait of Otranto.
On 20/22 December Cunningham and his Warspite group moved forward to meet the four merchant vessels of the ME.5 convoy and escort them to Alexandria. During this period Malaya and three destroyers escorted through the Sicilian Narrows the two empty merchant vessels (7,529-ton Clan Forbes and 7,529-ton Clan Fraser) of the MG.1 convoy heading from Malta to Gibraltar. On 20 December the Italian submarine Serpente attacked one of the escort’s destroyers, believing this to be Hyperion: the destroyer was not hit, but on the night of 21/22 December struck a mine near the island of Pantelleria and suffered severe damage. The destroyer Ilex attempted unsuccessfully to tow Hyperion, which was then sunk by Janus.
The ME.5 convoy was met in the area to the south of Sardinia by Vice Admiral Sir James Somerville’s Force 'H' in the form of the battle-cruiser Renown, fleet carrier Ark Royal, light cruiser Sheffield and six destroyers, and continued to Gibraltar without further incident.
On 21 December nine Fairey Swordfish torpedo bombers of Illustrious's Nos 815 and 819 Squadrons attacked the Italian torpedo boats Clio and Vega, which were escorting two Italian convoys, and of the latter sank the 6,511-ton merchant vessel Norge and 1,926-ton merchant vessel Peuceta. Early on the following day eight and seven of Nos 815 and 819 Squadrons' Swordfish aircraft attacked the part of Tripoli harbour in which the Italian submarines Dessič, Serpente and Bandiera were based for patrols in the area of Malta, but scored no hits.