'Herkules' was the German unrealised component of the Italian 'Esigenza C3' operation for the capture of the islands of Malta and Gozo using Axis airborne forces launched from Sicily (13 April/24 June 1942).

Scheduled for implementation in September 1942, this operation was to secure most of its element of tactical surprise by the delivery two airborne divisions (one German and one Italian) by parachute and glider into the southern part of Malta. An attack at Marsaxlokk Bay was also planned as a diversion to cover the main assault by the Italian navy, which was to land two or three assault divisions in the area to the south-east of Valletta.

After the initial assault, these 70,000 or so Italian troops would land by sea at two points to link up with the airhead created by the airborne forces. A number of special operations were to be carried out by Axis special forces to destroy key targets in the hours before the air landing, and the Italian navy would also be committed to a fleet action to protect the seaborne troops.

In their combined definitive form, therefore, 'Herkules' and 'Esigenza C3' would have been more than five times larger than 'Merkur', the airborne attack on Crete. The plan was postponed (effectively cancelled) at the end of July 1942 by Adolf Hitler, recalling the high casualties of the Luftwaffe in terms of both its aircraft and its airborne units during the execution of 'Merkur', on the later urging of Generalfeldmarschall Erwin Rommel, commanding the Panzerarmee 'Afrika' in North Africa, who insisted that the matériel and manpower resources for 'Herkules' would be better deployed in support of his offensive toward Egypt and the Suez Canal, which had reached a critical point offering the chances of major strategic success.

Hitler was correct in his fears about the number of casualties which might be expected, but with the operation’s termination the Axis lost its only realistic, if costly, opportunity to remove the Mediterranean bastion which had already played and was still performing so important a part in strangling the Axis maritime communications between Italy and Libya, upon which the very existence of the German and Italian land forces in North Africa depended.

'Merkur' was formally cancelled after the Axis defeat at Tobruk on 11 November 1942.

The overall plan was agreed at a meeting between Hitler and Benito Mussolini on 29/30 April 1942, and within this overall concept 'Herkules' was schemed by General Kurt Student’s XI Fliegerkorps, which planned a major operation using some 1,100 aircraft to transport and then support as assault force consisting of Generalmajor Richard Heidrich’s 7^th Fliegerdivision reinforced to a strength of 11,000 men with the 4^th Fallschirmjägerregiment and 5^th Fallschirmjägerregiment, and supported by two Italian formations, Generale di Divisione Enrico Frattini’s 185a Divisione paracadutista 'Folgore' and Generale di Divisione Gavino Pizzolato’s airlanding-trained 80a Divisione aviotrasportabile 'La Spezia' with 7,500 and 10,500 men respectively.

The German component of the aircraft to deliver the airborne forces was to comprise 500 Junkers Ju 52/3m transports, each carrying 18 men, in 10 Gruppen, 300 DFS 230 small assault gliders each carrying 10 men, and 200 Gotha Go 242 large assault gliders each carrying 23 men or a light vehicle/gun. There were also to have been 24 Messerschmitt Me 321 Gigant heavy gliders each capable of carrying up to 200 fully equipped paratroopers or one 25-ton tank. The Me 321 gliders were to be towed by the newly developed Heinkel He 111Z tug, a five-engined development of the He 111 medium bomber with two fuselages and two outer wing panels joined by a new centre section with three engines.

The Italian component of the delivery armada was to have comprised some 180 to 220 transport aircraft, mostly three-engined Savoia-Marchetti SM.75 machines each carrying between 24 and 28 men, SM.81 machines each carrying between 12 and 14 men, and SM.82 machines each carrying between 30 and 34 men.

Given the fact that it was only 90 miles (145 km) between the launch airfields in Sicily and the planned drop zones over Malta, the Axis planners worked on the basis of each transport aeroplane making four round trips per day to drop the single German and Italian airborne divisions onto the southern side of the island. Here the paratroopers had as their primary objectives the securing of the high ground behind the beaches over which the seaborne forces were to land, and the seizure of a nearby airfield so that the Axis transport aircraft could quickly land another division and supplies.

The size of the planned airborne operation dictated the construction of three dedicated glider strips some 25 miles (40 km) to the south of Monte Etna on Sicily. The airborne assault was to be combined with the amphibious assault by a force totalling 70,000 Italian troops. These latter were to make two amphibious landings on the southern side of the island: the larger and smaller efforts were to descend on locations designated as 'Famagosta' and 'Larnaca' respectively.

Also to be seized in this ambitious undertaking were the smaller islands of Gozo and Comino a short distance to the north-west of Malta, and other elements of the Axis plan were amphibious feints against St Paul’s Bay, Mellieha Bay and an area to the north-west of Valletta near the old Victoria Lines with the object of drawing British attention away from the real landing sites on the south-eastern side of Malta.

The airborne assault was to land during the afternoon and take the heights above the selected beaches, over which the troops delivered by the main assault convoy would begin their assault landing just before 24.00 on the first day of the operation. Most of the first-wave assault troops would be men of Generale di Divisione Giacomo Carboni’s 20a Divisione fanteria 'Friuli' (10,000 men) and Generale di Divisione Domenico Chirieleison’s 4a Divisione montagna 'Livorno' (9,850 men) of Generale di Corpo d’Armata Renato Coturri’s XXX Corpo d’Armata. Also included were the air force’s 1o Battaglione d’assalto (1,200 men), the Battaglione 'Loreto' (1,200 men), two marine battalions of the Reggimento 'San Marco' (2,000 men), three 'Camicie Nere' (blackshirt) battalions (1,900 men) and 300 men of the Nuotatori special forces unit of the Reggimento 'San Marco' specially trained in ocean swimming and beach assault.

The supporting armour comprised 19 Semovente 47/32 and eight Semovente 75/18 self-propelled guns plus 30 L3 light tanks.

A follow-up convoy was to deliver elements of Generale di Corpo d’Armata Carlo Rossi’s XVI Corpo d’Armata in the form of Generale di Divisione Giulio Perugi’s 26a Divisione montagna 'Assietta' (9,000 men) and Generale di Divisione Giulio Cesare Gotti Porcinari’s 54a Divisione fanteria 'Napoli' (8,900 men) along with attached artillery assets (3,200 men) and the rest of the 10o Reggimento corazatto (3,800 men).

Generale di Divisione Fernando Conte Gelich’s 1a Divisione montagna 'Superga' (9,200 men), one blackshirt battalion and a small detachment of the Reggimento 'San Marco' (1,000 men) were to land on the smaller island of Gozo early on the operation’s second day.

Additional armour intended for 'Herkules' included the 2^nd Kompanie of the Panzerabteilung zbV 66, a German unit partly equipped with captured Soviet tanks including 10 KV-1 and KV-2 heavy tanks that were to be landed by a force of at least 10 Italian motozattere (landing craft) with reinforced flooring and internal ramps to carry and off-load these vehicles. Other tanks in the unit included captured T-34 medium tanks, up-armoured German light tanks (five VK 1601 and five VK 1801 vehicles), 12 PzKpfw IVG battle tanks armed with 75-mm (2.95-in) guns, and 20 PzKpfw III medium tanks.

The Axis planning provided two days for the main amphibious assault and the landing of the follow-up convoy’s assets, though this was dependent on quick seizure of Marsaxlokk Bay, which would allow heavier artillery pieces and a much greater tonnage of supplies to be landed.

As it lacked sufficient landing craft to undertake a major amphibious assault, the Italian navy obtained the plans for the German shallow-draught Marinefährprahm Typ A and intended to have such craft built in Italian yards. These 220-ton craft could carry up to 200 fully equipped infantrymen, two or three medium tanks or an equivalent weight in cargo, and could unload directly onto an open beach via a drop-down bow ramp. Some 65 of these motozaterre had been built by July 1942, and about 50 of them would have been available for the invasion. Some 20 German MFPs were also transferred to the Mediterranean via the Rhône river to make up for an expected shortfall of Italian-built landing craft. More German-operated landing craft were transported to Italy via rail, this boost to the Mediterranean transport force including 12 Siebel catamaran ferries powered by car engines driving water propellers and armed with a mix of 88-mm (3.465-in) and 20-mm Flak guns, six Pionierlandungsboote Typ 39 each capable of delivering 20 tons of cargo, or two light vehicles, or 45 troops landed via clamshell doors at the bow, six Pionierlandungsboote Typ 40 enlarged versions of the Typ 39 each capable of delivering 40 tons of cargo, or three or four light vehicles or 80 to 90 troops, a company of 81 Sturmboot Typ 39 small plywood boats carrying up to six infantrymen and powered by outboard motors, and an assortment of large inflatable rafts each able to carry 25 troops. Some of the rafts were powered by outboard motors and others were were propelled by oars alone.

The Italians assembled a varied collection of other naval craft to transport the amphibious forces. These included two former Strait of Messina railway ferries each adapted to carry between four and eight tanks, 10 passenger ships each able to carry between 800 and 1,400 men, six former passenger ferries each able to carry 400 men, six cargo ships each able to carry 3,000 tons of supplies, 30 ex-trawlers each able to carry 300 men, five converted minelayers each able to carry 500 men, and 74 assorted motor boats each able to carry between 30 and 75 men. The Italians also requested the use of 200 more Sturmboote for an enhanced capability to deliver men from ship to shore.

Specialised landing equipment for 'Herkules' included the Seeschlange (sea snake) floating ship-to-shore bridge originally developed by the German army for 'Seelöwe'. Tested and validated in trials at Cherbourg in occupied France during the autumn of 1941, the Seeschlange comprised a series of linked modules (each transportable by rail) which could be towed into position to serve as a temporary jetty: moored ships could then unload their cargo either directly onto the 'roadway' or lower cargo onto it using their own lifting gear.

The Italian navy had the double task of protecting the invasion convoys from intervention by the British naval forces based in the Mediterranean, and of providing gunfire support during the landings. The force assigned to accomplish this included four battleships (Littorio, Vittorio Veneto, Caio Duilio and Andrea Doria), four heavy cruisers, eight light cruisers and 21 destroyers, which were to sortie from Messina, Reggio di Calabria, Augusta and Cagliari. The older Caio Duilio and Andrea Doria would each carry about 200 rounds of 320-mm (12.6-in) ammunition for shore bombardment.

Italian and German submarines were also to be deployed for reconnaissance and to intercept any British naval forces attempting to interfere with the landings. One submarine was to be stationed mid-way between Sicily and Malta and act as a guide beacon for the transport aircraft on their way to and from the drop zones. The Italians were confident they could defeat any daylight attacks by British warships, especially as General Hans Geisler’s (from 31 August General Otto Hoffmann von Waldau’s) X Fliegerkorps had secured daytime air superiority, but was altogether less confident about their ability to handle any British attacks by night. Lacking shipborne radar and only indifferently trained in night fighting training and equipment, the Italian navy had fared badly during the night action with British forces off Cape Matapan in March 1941 during 'Gaudo'.

The Italians were aware that a similar encounter off Malta could wreak havoc on the slow-moving Axis invasion convoys, leaving the airborne forces cut off and imperilling the Axis chances of taking the island. The Italian navy had made some efforts to rectify this situation by equipping the battleship Littorio with an experimental EC-3/bis Gufo radar in August 1941, but this was unreliable and not replaced by a more reliable and more effective production-standard Gufo equipment until September 1942. In September 1941, while awaiting delivery production-standard radars, the Italian navy had asked the Germans for a FuMO 24/40 G DeTe radar for installation on its newest destroyer, Legionario, which was still under construction. By March 1942 the requested set had been delivered and installed, and a small group of Italian ratings had been trained in Germany to use it. Operational testing had started during that spring and, by May, Ammiraglio di Armata Angelo Iachino, the fleet commander, had submitted a report praising its performance.

In 1942 the British military establishment on Malta was centred on 15 infantry battalions (11 British commonwealth and four Maltese) organised into four brigades and totalling some 26,000 men. Armour support was provided by the 1^st Independent Troop of the Royal Tank Regiment equipped with Matilda Mk II infantry tanks armed with a 2-pdr gun and Vickers Mk VIC light tanks armed with two machine guns. The British armoured strength is uncertain, but it seems likely that there were no more than 10 tanks on the island. Other British land strength included the 12^th Field Regiment with 24 25-pdr field gun/howitzers able to provide indirect fire support out to a range of 12,000 yards (10975 m) and thereby able to cover most of the island from protected static positions. Malta’s fixed defences included 19 coastal guns varying in calibre from 12 to 16 in (305 to 406 mm), 130 smaller coastal guns in the calibre range from 4.7 to 9.2 in (119 to 234 mm), and 112 heavy and 144 light anti-aircraft guns.

A date near the middle of July 1942 was set for the invasion, partly to allow time for troops to be assembled from other front-line positions, and partly because Hitler believed the Italian navy to be no match for the Royal Navy. Commanding the Panzerarmee 'Afrika' in North Africa, Rommel initially supported the concept of seizing Malta to the point that he personally asked Hitler to allow him to command the invasion forces. His reasons were militarily clear and compelling: to hinder the Allied troops fighting in Africa, and to remove the constant threat to the convoys delivering supplies, oil and men to North Africa. Rommel placed so great an emphasis on the need for such an operation that the head of the Luftwaffe, Reichsmarschall Hermann Göring, opposed the invasion on the grounds that it could, and indeed probably would, result in another near-disaster for his paratroops, as had happened on Crete in 'Merkur'.

Generalfeldmarschall Albert Kesselring, the Oberbefehlshaber 'Süd', was also an advocate of 'Herkules' until he was persuaded that too many air and ground units had been siphoned off to support Rommel’s North African operations, thereby significantly diminishing any chance of success. Together with Hitler’s concerns about Italian naval incapacity and casualties in the airborne forces and their supporting aircraft, this finally led to the abandonment of the Axis forces' plan for the invasion of Malta.