Operation Excess was a series of British supply convoys to Malta, Alexandria and Greece in January 1941. The operation was the first to encounter Luftwaffe anti-shipping aircraft over the Mediterranean Sea and all the convoyed freighters reached their destinations. The destroyer Gallant was disabled by Italian mines and Axis bombers severely damaged the cruiser Southampton and the aircraft carrier Illustrious.

Italy's declaration of War on 10 June 1940 brought the Second World War to the Mediterranean Sea and placed the Regia Aeronautica astride the traditional British sea route to Indian Ocean ports, while the Regia Marina roughly tripled the numbers of battleships, cruisers and submarines available to challenge British sea power. The Royal Navy had held the eastern Mediterranean and France the western Mediterranean but the Second Armistice at Compiègne removed the French navy from the alliance on 25 June 1940. From bases at Gibraltar and Alexandria, the Royal Navy attempted to convoy supplies to Malta to maintain it as a base in the central Mediterranean. As Italy attacked Egypt from Libya in September 1940 and Greece from Albania in October 1940, the Royal Navy maintained most of the Mediterranean Fleet at Alexandria and used Force H at Gibraltar for raids. British successes in early November 1940, including providing help to the Greeks to defeat the Italian offensive in Greece and the Royal Navy disabling Italian battleships Littorio, Conte di Cavour and Duilio at the Battle of Taranto, provided incentive and opportunity to supply Malta and Greece.

Convoy MC 4 consisted of four freighters at Gibraltar, Clan Cumming, Clan MacDonald and Empire Song carried materiel destined for Piraeus. Essex carried 3,000 long tons (3,000 t) of seed potatoes, 4,000 long tons (4,100 t) of ammunition and twelve crated Hawker Hurricanes for Malta.

Convoy MW 5 consisted of the Freighters Breconshire and Clan Macaulay at Alexandria with cargo bound for Malta.

Convoy ME 6 was made up of nine freighters waiting at Malta for passage to Alexandria.

Force A comprised HMS Warspite, Valiant, Nubian, Mohawk, Dainty, Gallant, Greyhound, Griffin, Jervis and Illustrious to sail from Alexandria, covering convoys MC 4, MW 5 and ME 6 east of the Skerki Banks.

Force B of HMS Gloucester, Southampton, Ilex and Janus would carry five hundred soldiers and airmen from the Aegean to Malta and join convoy MC 4 after dropping their passengers in Malta.

Force C was to screen Convoy MW 5 with HMS Calcutta, Defender and Diamond.