Italian Mare Nostrum was the name given during World War II, by Benito Mussolini and his fascist propaganda to the Mediterranean Sea.

The Mare Nostrum of Mussolini
The Mediterranean was called Mare Nostrum (Latin for "Our Sea") during the centuries of the Roman Empire, an empire that Fascism intended to recreate after the conquest of Ethiopia in 1936.

Mussolini wanted to re-establish the greatness of the Roman Empire and believed that Italy was the most powerful of the Mediterranean countries after World War I. He declared that "the twentieth century will be a century of Italian power" and created one of the most powerful navies of the world in order to control the Mediterranean Sea.

However, the nation that really dominated the Mediterranean in 1940 was the United Kingdom, as the British had strong naval bases in Gibraltar, Malta and Cyprus. The British also controlled the Suez Canal, along with the French; the French Third Republic had a relatively powerful navy, and controlled the African Maghreb. Only after the conquest of Greece and Yugoslavia, in April 1941, Mussolini started to talk about an Italian dominated Mediterranean sea.

In 1942 Mussolini dreamed to create a Greater Italia in his "Mare Nostrum" and promoted the fascist project -to be realized in a future peace conference after the expected Axis victory- of an enlarged Italian Empire, stretching from the Mediterranean shores of Egypt to the Indian Ocean shores of Somalia and eastern Kenya. All these projects disappeared with the final Italian defeat of September 1943.

Italian-controlled seashores

Italy controlled (directly or indirectly) the seashores of these Mediterranean countries, when Mussolini spoke and boasted of an "Italian Mare Nostrum" in 1941/1942/1943:
 France: From June 1940 to September 1943, the Menton riviera (between Monte Carlo and the Italian border). From November 1942 to September 1943, the delta of the Rhone river to the French Riviera.
 Corsica: From November 1942 to September 1943.
 Italy: From the Alps to Istria. The Governatorato di Dalmazia was added between between April 1941 and September 1943.
 Yugoslavia: From April 1941 to September 1943, all the coasts of Croatia and Montenegro.
 Albania: From 1939 to September 1943 all the coast. (Saseno island was Italian).
 Greece: From April 1941 to September 1943, all the continental coast from Epirus to Thessalia and most of the Aegean Islands (with eastern Crete).
 Dodecanese: Italian islands from WWI to September 1943.
 Tunisia: From November 1942 to May 1943.
 Libya: Italian from 1911 to 1943.
 Egypt: The western coast up to El Alamein was intermittently controlled by the Axis, between June 1940 and November 1942.

Battle of the Mediterranean in WWII

When France collapsed in 1940, Mussolini started to expand the Italian maritime control on the central Mediterranean, attacking British possessions. The ensuing Battle of the Mediterranean had many changes of fortune and finished with the victory of the Allies.

There were a series of surface actions (e.g., Battle of Cape Matapan, Battle of Punta Stilo, Battle of Cape Teulada, Second Battle of Sirte, Battle of Mid-June, Battle of Mid-August ) between Allied navies and the Italian Regia Marina, during which the British, able to replace losses with warships redeployed from other theatres, finally gained the upper hand.

The Battle of Taranto in 1940 was a successful air attack on the Italian Navy at anchor when 21 British torpedo bombers sunk one battleship and damaged two others.The Italian Navy slowly recovered from that attack.

The Italian Navy's most successful attack, however, was when human torpedo divers planted mines on British battleships in Alexandria (Egypt) harbour (19 December 1941), and the HMS Queen Elizabeth and HMS Valiant were sunk  . After these sinkings (and the contemporary destruction of the British Force K), the Italian Navy obtained for some months the nearly complete control of the central Mediterranean.  In this way the Regia Marina was able to deliver the military supply and oil for the Axis victory of Tobruk and for the advance toward El Alamein in Egypt.

Regia Aeronautica

The Italian Regia Aeronautica entered the war with 3296 airplanes (1332 Bombers and 1160 "Caccia", as were called the Fighters in Italian) distributed in all the Italian Empire, but only 1796 were in perfect fighting conditions. Most were old "wood" models, and could not match the British aircraft in 1940.

But in April 1941, when Italy started together with the Germans the coordinated Axis attack in the Mediterranean (in the Balkans and in Libya), the Italian Air Force had the new and competitive Macchi C.202, able to fight successfully the British Spitfires.  These airplanes (with the new Reggiane Re.2002) took control of the Malta and Libyan airspace (together with the German military aircraft) during the successful campaign of General Rommel in Tobruk.

Only at the beginning of 1943 appeared the modern Macchi C.205 and Reggiane Re.2005, but they could not match the overwhelming superiority of the American Air Force.

One of the most renown and important branches of the Regia Aeronautica was the "torpedo bomber" group. In 1941 and 1942, Italian pilots, mostly flying the three-engined, medium bomber Savoia-Marchetti SM.79 "Sparviero" , inflicted considerable losses to Allied shipping in the Mediterranean Sea.

The only four engine heavy bomber of the Regia Aeronautica was the Piaggio P.108 B. In the 274th Long-Range Bombardment group these bombers made many long range bombardments of Gibraltar from Sardinia in summer 1942   and reinforced in this way the Regia Aeronautica supremacy during those of months in the Italian Mare Nostrum.

Regio Esercito

The Italian Army (Regio Esercito) entered the war with 73 divisions (and one fascist Legion of "Blackshirts"), but only 19 were fully operational for combat in June 1940. Italy during the first years of WWII had only small and medium tanks (Fiat M13/40 and Fiat M15/42), that were no match for the Allies tanks. Only in summer 1943 the Italians developed a heavy tank (the P40 tank)  , but just 5 were ready for combat when Italy signed the armistice.  The Italian Army had good antitanks (like the Semovente 75/18)    and reliable armoured cars (like the AB 41) .

Slowly the initial Italian setbacks (suffered mainly in the African colonies) were corrected with German help and in spring 1941 the Italians started an offensive in the Balkans (Greece and Yugoslavia) and in North Africa (Libya).

In summer/autumn 1942 Italy controlled the European seashores of the Mediterranean from the Rhone river in occupied France to Mount Olympus in Aegean Greece. A similar situation happened in the African shores of the Mediterranean Sea, where Mussolini's control went from Tunisia to El Alamein in Egypt. This Italian domination was increased by the fact that most of the remaining shores of the Mediterranean were controlled by the fascist Spain of General Franco, the France of Vichy and the Turkey of Kemal Atatürk, all of them with friendliness toward Mussolini.

In those months Mussolini referred to the Mediterranean Sea as Mare Nostrum, in the same manner as the Romans had done when they dominated the Classical World.  However, the Roman Mare Nostrum lasted for roughly six hundred years, while Mussolini's Mare Nostrum lasted a few years until the Italian armistice in September 1943.

All the overseas possessions of Italy in the Mediterranean Sea (Dodecanese, Libya, Saseno island, etc.) were lost formally as a result of the Treaty of peace with Italy (1947).

Regia Marina and Italian Mare Nostrum

When Italy entered World War II on 10 June 1940, the Italian Royal Navy (Regia Marina) was the fourth largest navy in the world.  The Italian Navy had a mix of modernised and new battleships and challenged the Allies, mostly the British Royal Navy, for supremacy of the Mediterranean Sea.

Air support was provided by the Italian Air Force Auxiliary to the Navy (Aviazione Ausiliara per la Marina), the naval air service during wartime. The Air Force Auxiliary was in charge of all land-based aircraft, shore-based hydroplanes amongst of vessel-based aircraft, and hydroplanes of Italian Navy.

Italian warships had a general reputation as well-designed and good-looking.  But some Italian cruiser classes were rather deficient in armour.  All Italian warships lacked radar for most of the war, although the lack of radar was partly offset by the fact that Italian warships had good "rangefinder" and "fire-control" systems.  In addition, whereas Allied commanders at sea had discretion on how to act, Italian commanders were closely and precisely governed by Italian Naval Headquarters (Supermarina).  This could lead to action being avoided when the Italians had a clear advantage (e.g., During "Operation Hats"  . Italian Naval Headquarters was conscious that the British could replace ships lost in the Mediterranean, whereas Italian Navy resources were limited).

The Allies had "Ultra" intercepts, which predicted the Italian movements, and radar, which enabled them to locate the ships and range their weapons at distance and at night. The better air reconnaissance skills of the Fleet Air Arm and their close collaboration with surface units were other major causes of the initial Italian defeats (like in the Battle of Cape Matapan).

The most successful attack performed by the Italian Navy involved divers planting mines on British battleships in Alexandria harbour (19 December 1941): HMS Queen Elizabeth and HMS Valiant were sunk in shallow water by the maiali of Luigi Durand De La Penne.   

On the same night, Force K, comprising three cruisers and four destroyers based at Malta, became stranded in an Italian minefield off Tripoli. A cruiser (HMS Neptune) and a destroyer (HMS Kandahar) were lost, three other ships were seriously damaged, and more than 900 men died. Force K was put out of action and Malta's offensive capabilities were reduced to a minimum.

This sudden series of Allied defeats allowed the Regia Marina to achieve naval supremacy in the central Mediterranean, her supply routes were almost untouched by the enemy for several months. This is the beginning of nearly one year in which the Mediterranean sea was effectively an "Italian Mare Nostrum".
 
The Italian fleet also took advantage of the situation and moved onto the offensive, blocking or decimating at least three large Allied convoys bound for Malta. This led to a number of naval engagements, such as the Second Battle of Sirte, the Battle of Mid-June or Operation Harpoon (plus Operation Vigorous) and finally to Operation Pedestal, all of them  favourable to the Axis but sufficient supplies had been delviered to Malta for it to survive as a British base. The biggest success of the Italian Fleet was the aerial and surface attack on the Harpoon convoy, which sank several Allied warships and damaged others. Only two transports of the original six reached Malta. This was the only undisputed squadron-size victory for Italian surface forces in World War II.

During these months the Regia Marina even planned an attack to New York harbour for December 1942, but it was delayed for many reasons and was never done  .

However, this was only a brief happy time for Mussolini. The oil and supplies brought to Malta, despite heavy losses, by Operation Pedestal in August and the Allied landings in North Africa, Operation Torch, in November 1942, turned the fortunes of war against Italy. After years of stalemate, the Axis forces were ejected from Libya and Tunisia in six months after the Battle of El Alamein, while their supply lines were harassed day after day by the growing and overwhelming aerial and naval supremacy of the Allies in what has just been the Mussolini's "Italian Mare Nostrum".

The Regia Marina performed well and bravely in its North African convoy duties, but remained at a technical disadvantage. The Italian ships relied on a speed advantage, but could easily be damaged by shell or torpedo, due to their relatively thin armour. The fatal and final blow to the Italian Navy was a shortage of fuel, which forced her main units to remain at anchor for most of the last year of the Italian alliance with Germany  .

Main naval battles in the Italian Mare Nostrum

From summer/fall 1941 to November 1942 the Mediterranean sea was effectively an "Italian Mare Nostrum", fully controlled by the Italians in the central area around the Italian peninsula and Tunisia/Libya. These were the main battles/events in those months:

 Attack on the British base at Suda Bay, Crete by destroyers Crispi and Sella, both transporting explosive motor boats: HMS York beached and abandoned and one oil tanker sunk (26 March 1941).
 First Battle of Sirte (1941): Naval engagement tactically inconclusive ; British warships ran on a minefield in the aftermath, while waiting for an Italian convoy off Tripoli. They lost a cruiser and a destroyer; more than 800 British seamen died in the incident.
 Sinking of Battleships HMS Queen Elizabeth and HMS Valiant in Alexandria Harbor, by Italian frogmen (19 December 1941)
 Second Battle of Sirte (22 March 1942): escort battered by Italian battleship Littorio, but still able to break contact; cargo ships destroyed by aircraft attack before they could reach Malta as result of the battle.The British had 3 light cruisers and 6 destroyers damaged.
 Battle of Mid-June (1942), also known as Operation Harpoon (destroyer HMS Bedouin, tanker Kentucky, steamer Burdwan and merchantman Chant sunk by combined air and surface action) and Operation Vigorous, when the Italian Fleet blocked a 11 cargo ships convoy (cruiser HMS Hermione and four British destroyers sunk by German E-boats and axis aircraft).
 Battle of Mid-August (1942), also known as Operation Pedestal: cruiser HMS Manchester and four merchantmen sunk by Italian Torpedo Boats. Two other cruisers and three steamers sunk by submarine and air strikes. It was the last major tactical success for the Italian forces, supported by the Germans, against the Malta convoys.
 Operation Agreement, 14 September 1942: A Royal Navy attempt against Tobruk harbour ended in disaster when aerial, coastal and naval Italian forces launched a swift counter-attack; more than 700 British servicemen were killed.

Photos

Notes

Bibliography
 Blitzer, Wolf. Century of War. Friedman/Fairfax Publishers. New York, 2001 
 Buell, Hal. World War II, Album & Chronicle. Tess Press. New York, 2002 .
 De Felice, Renzo. Mussolini l'Alleato: Italia in guerra 1940-1943. Rizzoli Ed. Torino, 1990.
 Fleming, Thomas. The New Dealers' War. Perseus Books. New York, 2001 
 Holland, James. Fortress Malta: An Island Under Siege, 1940-1943. England: Cassell Military, 2004 .
 Lamb, Richard. Mussolini as Diplomat. Fromm International Ed. London, 1999 
 Petacco, Arrigo. Le battaglie navali del Mediterraneo nella seconda guerra mondiale Mondadori Editore. Milano, 1976
 Weinberg, Gerhard. A World at Arms: A Global History of World War II New York, 2005

Other websites
   History of the Regia Marina in World War II 	 	
  Italian Navy in the Mediterranean Sea
 Battle of Mid-August (in Italian)
 The Italian Airforce in WWII (in Italian)
 Italian Army vehicles and tanks in WWII: brief history 
 History of sinkings by Italian "Maiale" human torpedo (in Italian)	
  10 pages of photos of Italian Navy from www.battleships-cruisers.co.uk

World War II
History of Italy