The 'Battle of the Espero Convoy' was a naval engagement fought between British-led and Italian forces as the first surface engagement in the Mediterranean Sea in World War II (8 June 1940).

In this episode, three modern Italian destroyers made a run from Taranto for Tobruk in Libya to transport 'Blackshirt' anti-tank units to face any possible armoured attack by British forces westward from Egypt. Coincidentally, Admiral Sir Andrew Cunningham’s Mediterranean Fleet was at sea from Alexandria to conduct a destroyer anti-submarine sweep around Crete and provide cover for three Allied convoys (one from Turkey and two from Malta) to Egypt. British aircraft from Malta spotted the Italian destroyers and Vice Admiral J. C. Tovey’s 7^th Cruiser Squadron was directed to make an interception. There developed a running fight to the south-west of Crete, in which the destroyers were impeded by their cargoes and an adverse sea.

The Italian destroyer Espero, under the command of Capitano di vascello Enrico Baroni, was sunk while covering the escape of the other two destroyers, Zeffiro and Ostro to Benghazi. The British ships rescued 53 of the 225 crew and passengers, of whom three later died of their wounds. The British and Australian cruisers expended a very considerable quantity of main-armament ammunition and the Malta convoys had to be postponed until they had replenished from the 800 6-in (152.4-mm) shells in reserve. The AS.1 convoy from Turkey had arrived safely by 3 July.

Italian supply shipments to Libia Italiana (Italian Libya) were landed at the ports of Tripoli (2,000 tons per day), Benghazi (1,000 tons per day) and Tobruk (less than 1,000 tons per day), with some minor deliveries possible to Derna and Bardia. Once landed, the supplies and reinforcements had to be moved toward the front by lorry or small coastal craft. In late 1939, assuming overwhelming Anglo-French naval superiority, Maresciallo d’Italia Pietro Badoglio, the Italian army’s chief-of-staff, established a policy of maintaining internal security and possessing supplies sufficient for one year. On 9 April, Badoglio met the three service chiefs and announced the '…firm decision of the Duce to intervene at such time and in such places as he will choose', and ordered that the Regio Esercito was to remain on the defensive as the Regia Marina and the Regia Aeronautica undertook offensive operations. On 30 May, Badoglio ordered the service chiefs to be ready for hostilities by 5 June: at this time, the Italian war aims were to fight in parallel with Germany, to dominate the Balkans, to establish a land route to Africa Orientale Italiana (Italian East Africa) and to ensure continued access to Spain and the Black Sea.

On 11 April, the naval chief-of-staff, Ammiraglio d’Armata Domenico Cavagnari, reported his doubts about the possibility of offensive action against opponents who could replace losses far more speedily than was possible for Italy. Going to war with a defensive strategy was unprecedented and, at the end of the war, Italy might have no territorial gains, no navy and no air force. The navy planned to keep its forces concentrated to generate maximum firepower, which precluded the protection of merchant shipping on all but the rarest of occasions: the presence of the French to the west and British to the east meant that convoying ships from Italy to Libya would be impossible. Benito Mussolini, the Italian dictator, refuted such doubts by predicting a war of three months' duration at a time when Libya had six months' supplies.

Only on 10 June did Mussolini direct that the military forces in Libya be reinforced for offensive operations and that the Regia Marina was to protect the supply routes in the central Mediterranean. On 13 June, the first request arrived from Libya for the despatch of 'indispensable' supplies. In 1940, the Regia Marina had two modernised battleships and 19 cruisers with which to oppose the British and French Mediterranean fleets of three aircraft carriers, 11 battleships and 23 cruisers, giving the Allies a 4/1 tonnage superiority, which could be reinforced from outside the Mediterranean at will. The British ships were based at Gibraltar and Alexandria, with no ships at Malta, and the French ships were based at Toulon in southern France and Bizerte in northern Tunisia, while the primary Italian bases were Naples and Taranto, with small forces based in Sicilian ports. The Italian forces could unite by passing through the Strait of Messina between Sicily and the Italian mainland, but these narrows were an obvious place for an ambush.

The Regia Marina had advocated the retention of a naval air arm after World War I, but after the creation of the Regia Aeronautica in 1923 lost control of naval aviation. The proponents of land-based air power disdained the naval preference for aircraft carriers and specialist aircraft in favour of land-based aircraft fulfilling all of the requirements of maritime aviation, apart from an acceptance of the need for reconnaissance by 'Aviation for the Navy' in which the navy possessed operational control and sent observers aloft. The Regia Aeronautica followed the theory of independent air operations 'according to its own rules' and paid scant attention to the needs of the Regia Marina. Promising experiments with air-launched torpedoes from 1918 to 1922 were stifled by the new independent air force, and even after the example of British experiments with torpedo-bombers, attempts by the Regia Marina in 1938 to gain control of a naval torpedo-bomber force failed.

It was on 10 June 1940 that Italy declared war on the UK and France. Badoglio expected a British advance into the Cyrenaican eastern part of Libya led by armoured forces. On 11 June, the 3a Divisione incrociatori and 7a Divisione incrociatori conducted an abortive patrol in the Strait of Sicily; on the next morning, two British cruisers were spotted to the south of Crete heading to the west and the 3a Divisione incrociatori and two destroyer squadrons were sent to patrol the route to Malta. The 3o Squadrone incrociatori and 8o Squadrone incrociatori patrolled the Ionian Sea and two destroyer squadrons sailed between Sicily and Malta. On 12 June, an Italian 'Giovanni Berta' class naval trawler was sunk off Tobruk by two British cruisers and four destroyers; the Italian submarine Alpino Bagnolini sank the British light cruiser Calypso to the south of Crete. From 11 June to 16 August, the specialist Gruppo 'Orata' dredged up the seven British cables from the seabed around Malta and took away thousands of yards of cable to prevent them from being reconnected.

The difficulty of escorting merchant ships to Tobruk led to a decision to use warships and submarines in the supply delivery role. On 19 June, the submarine Zoea sailed for Tobruk carrying ammunition, and on the following day a destroyer squadron led by Artigliere departed Augusta in Sicily for Benghazi carrying troops and anti-tank guns. On 25 June a convoy with escorts left Naples for Tripoli with supplies and 1,727 troops; the submarine Bragadin departed for Libya with equipment for the airfield at Tobruk. The Italian 'Turbine' class destroyers of the 2o Squadrone cacciatorpediniere (Espero, Zeffiro and Ostro was selected, for its ships' high speeds, to transport anti-tank units, Two smaller World War I-era escort vessels, Pilo and Giuseppe Missori with 52 troops and additional supplies, departed Taranto independently for Tobruk some hours later.

On 27 June, five British destroyers were to depart Alexandria on an anti-submarine sweep near the Ionian island of Kythira and then steam to Malta to form the close escort for the MF.1 and MS.2 fast and slow convoys to Alexandria. Intelligence about Italian submarines led to the sweep being diverted through the Kasos Strait, to the east of Crete, then north of the island, thence past Kythira to Malta. Short Sunderland four-engined flying boats of the RAF’s No. 201 Group, based in Malta, were to co-operate with the naval operations in the Ionian Sea. On the Italian declaration of war, the passenger liner El Nil, which was on passage from Marseilles to Egypt, Knight of Malta and interned Italian ship Rodi were at Malta, and in 'MA3' these ships constituted the 13-kt MF.1 fast convoy. Five slower ships (Zeeland, Kirkland, Masirah, Novasli and Tweed) carrying naval stores for Alexandria constituted the 9-kt MS.1 slow convoy, which was to depart Malta for Alexandria. MF.1 carried civilians being evacuated from Malta, and the virtually entire Mediterranean Fleet was to sortie to protect the convoy in the 'MA5' operation. The AS.1 convoy of seven ships was to sail from the Dardanelles to Egypt, four ships joining from Thessaloniki, Piraeus and Smyrna, escorted by the light cruisers Capetown and Caledon of the 3^rd Cruiser Squadron and the destroyers Garland, Nubian, Mohawk and Vampire, due to depart from Cape Helles early on 28 June.

The timing of the departures of these disparate elements was arranged so that on 30 June the three convoys would be at Position K to the south of Cape Matapan, about halfway between Malta and Alexandria. Five light cruisers of the 7^th Cruiser Squadron (also known as Force 'C') under the command of Vice Admiral J. C. Tovey, with the 1^st Cruiser Division ('Leander' class Orion (flag), Neptune and Australian Sydney each with eight 6-in/152.4-mm guns), and the 2^nd Cruiser Division, and the 'Town' class Liverpool and Gloucester each with 12 6-in (152.4-mm) guns, were to sail to the west of Crete near Position K.

The 1^st Battle Squadron, under the command of Rear Admiral H. D. Pridham-Wippell, with the battleships Royal Sovereign and Ramillies, the aircraft carrier Eagle and the 2^nd Destroyer Flotilla, were to be to the south-west of Crete also near Position K, ready to intervene if required. At 18.00 on 26 June, Caledon, Garland and Vampire departed Alexandria to rendezvous with Capetown, Nubian and Mohawk on the following day while heading for the Dardanelles. A dawn on 27 June, five ships of the 2^nd Destroyer Flotilla departed Alexandria, and at 11.00 the 7^th Cruiser Squadron left for Position K.

As the sun set, the 2^nd Destroyer Flotilla (Voyager, Dainty, Decoy, Defender and Ilex) was 230 mi (370 km) to the north of Alexandria. At 18.28, while 115 miles (185 km) to the south-east of Crete, the flotilla spotted a submarine, Console Generale Liuzzi, which quickly dived. Four of the destroyers made depth charge attacks, and after the fifth attack an oil slick was seen and trailed by Dainty. The submarine had been badly damaged by the depth charging and was eventually forced to the surface. After a 90-minute hunt the submarine was seen again at a distance of 2,500 yards (2285 m) and two destroyers fired on the boat. A white light was taken to indicate a surrender, and Dainty moved closer and began to take on survivors, along with other destroyers which lowered boats to pick up the Italians who had taken to the water. According to one British source, 3 hours 15 minutes elapsed before the last two men from the submarine were taken off and the boat was sunk with depth charges. According to Italian sources, Console Generale Liuzzi was scuttled by its crew; 10 men were killed in the engagement, including the boat’s commander, Tenente Lorenzo Bezzi, who went down with the submarine.

On 28 June, the Italian destroyers of the 'Espero' convoy were sighted at 12.10 by a Sunderland flying boat of the Malta-based No. 228 Squadron in a position about 58 miles (93 km) to the west of the island of Zakynthos in the Ionian Sea, to the west of Greece and about 173 miles (278 km) from Position K. The flying boat’s crew gave no course for the destroyers, and the Italian ships were thought to be heading for the island of Kythira. At 16.10 the 7^th Cruiser Squadron turned to the north to intercept the Italian ships, and at 16.40 a sighting by another Sunderland had the Italian warships still heading to the south in a position about 40 miles (65 km) from Orion. Tovey ordered a turn to the south-west and an increase in speed to 25 kt. The cruisers steamed on a course of 180°: the 1^st Cruiser Division (Orion, Neptune and Sydney) to overhaul the Italians to starboard and the 2^nd Cruiser Division (Liverpool and Gloucester) about 6 miles (9 km) apart from them, to overtake them to port.

The Italian destroyers were steaming to the south-east at high speed when they were spotted by Liverpool at 18.30, about 120 miles (190 km) to the north of Tobruk. The cruiser opened fire three minutes later at a range of 18,000 yards (16460 m). The Italian ships had the legend speed to outrun the cruisers, but their age, heavy loads and the sea state meant that the British ships slowly overhauled them. The Italians had been taken by surprise and could not launch torpedoes because of their deck cargoes, but they were nonetheless difficult to hit as they made smoke, darkness gathered and the ships sailed toward the afterglow of the sun. At 19.05 Neptune reported torpedoes and the British ships changed course to comb the spread. The 2^nd Cruiser Division concentrated its fire on Espero, and by 19.20 had closed the range to 14,000 yards (12800 m), and the 1^st Cruiser Division turned 50° to starboard to bring all their turrets to bear, but Espero was not hit until the 15^th salvo. Baroni realised that his overloaded ships were doomed and decided to sacrifice Espero to enable the other two to escape, made smoke and manoeuvred evasively as Zeffiro and Ostro raced to the south-west. At 20.00 Espero was hit and brought to a stop.

As night was falling and his ships were running short of ammunition, Tovey abandoned the chase 10 minutes later and changed course for Malta. Tovey ordered Sydney to sink Espero, and when at 6,000 yards (5485 m) received two shells from Espero and replied with four salvoes, scoring hits. Espero began to burn from the bow to midships, and at 20.25 Sydney closed to 2,000 yards (1830 m) astern of the destroyer. Men jumped from the burning ship and there was an explosion near the bridge. At 20.40, with a list of almost 90°, Espero sank. Sydney lowered both of her boats to rescue survivors and used Jacob’s ladders and bosun’s chairs to bring them aboard. The glare from Espero before she sank and the presence of Italian submarines led to the rescue effort being ended at 22.19 after all 47 survivors in sight had been collected. Sydney left behind one of her cutters with oars, sails, foodstuffs, water and rifles, illuminated with a signal projector so that any remaining survivors could board it. Three of the survivors died before the ship reached Alexandria and six others were found alive on a raft by the Italian submarine Topazio 14 days later.

In an engagement lasting about 2 hours 10 minutes, the ships of the 7^th Cruiser Squadron had fired about 5,000 shells. An Italian 120-mm (4.72-in) shell hit Liverpool 3 ft (0.91 m) above the waterline but caused little damage. Some of the prisoners on Sydney disclosed the purpose of the operation, that Espero had a company of 225 men and passengers embarked and that Baroni had been killed in the explosion near the bridge. Other survivors, including two officers, later questioned by an Italian enquiry commission about the loss of Espero, instead stated that Baroni had survived the explosion with only minor wounds but had decided to go down with his ship.

The British cruisers' ammunition expenditure exacerbated a shortage of 6-in (152-mm) ammunition at Alexandria, where only 800 such shells were in stock. The 'Battle of the Espero Convoy' demonstrated that a daylight naval action at long range was likely to be indecisive and wasteful of ammunition.

The 2^nd Cruiser Division was so short of ammunition that it returned to Alexandria and the Malta convoys were postponed. The 1^st Cruiser Division reached Alexandria on 1 July, having also been ineffectually bombed. The AS.1 convoy from the Aegean Sea was attacked from 29 June to 1 July by Italian aircraft based in the Dodecanese islands group, but reached Alexandria and Port Said undamaged on 2 and 3 July. The shortage of ammunition and the threat posed by Italian submarines led to the two Malta convoy sailings being postponed for two weeks, followed by the MF5 operation, culminating in the 'Battle of Punta Stilo' on 9 July.

At dawn on 29 June, the 2^nd Destroyer Flotilla caught the submarine Uebi Scebeli on the surface 184 miles (296 km) to the west of Crete. The submarine dived and was depth charged by three of the destroyers, which forced the boat to the surface, where survivors were rescued. Dainty sank the submarine with gun fire at 08.20. The destroyers then headed for Alexandria, arriving at about 19.00 on 30 June. The prisoners talked of a submarine patrol line between Crete and the North African coast and two destroyers were despatched from Alexandria to Derna on an anti-submarine sortie. The ships detected a submerged submarine on 1 July, attacked and claimed its sinking, but after the ships had returned on 2 July the claim was disallowed. Zeffiro and Ostro had reached Benghazi on 29 June and arrived at Tobruk shortly after that, and the smaller Pilo and Missori also reached Libya after being diverted to the port of Tripoli.

On 5 July, nine Fairey Swordfish single-engined biplane torpedo-bombers of the Fleet Air Arm’s No. 813 Squadron, flew from Sidi Barrani in western Egypt to attack the ships in Tobruk harbour. The Swordfish aircraft were escorted by 12 fighters of the RAF’s No. 33 Squadron and machines of the RAF’s No. 211 Squadron strafed the airfield, damaging eight Fiat CR.42 single-engined biplane fighters, also flying several reconnaissance sorties. The Swordfish aircraft dropped seven torpedoes in the harbour and sank the destroyer Zeffiro as well as the merchant vessels Manzoni and Serenitas. The destroyer Euro and the liner Liguria were damaged. On the evening after the attack, the Fleet Air Arm’s No. 830 Squadron from Malta bombed the airfield at Catania in Sicily. Capetown and Caledon of the 3^rd Cruiser Squadron, with four destroyers, bombarded the port of Bardia from a range of 9,000 yards (8230 m) at dawn on 6 July and hit two ships, before standing by to assist the crews of any aircraft damaged on the Tobruk raid; Italian aircraft attacked the ships to no effect. The guns of Zeffiro were salvaged from the harbour and sent to Bardia to augment the coastal defences.