The Adriatic campaign of 1807–1814 was a minor theatre of war of the Napoleonic Wars in which the Royal Navy, assisted by Austrian, Montenegrin and Greek troops, attacked the combined forces of the First French Empire, Kingdom of Italy and Kingdom of Naples in the Adriatic Sea from 1807 to 1814. Much of the region was under direct or indirect French control, coming under France's domination as a result of Treaty of Pressburg which brought an end to the War of the Third Coalition.

Control of the Adriatic brought numerous advantages to the French Navy, allowing rapid transit of troops from Italy to the Balkans and Austria for campaigning in the east and giving France possession of numerous shipbuilding facilities, particularly the large naval yards of Venice. From 1807, when the Treaty of Tilsit precipitated a Russian withdrawal from the Septinsular Republic, the French Navy held naval supremacy in the region. The Treaty of Tilsit also contained a secret clause that guaranteed French assistance in any war fought between the Russians and the Ottoman Empire. To fulfil this clause, Napoleon would have to secure his supply lines to the east by developing the French armies in Illyria. This required control of the Adriatic against increasingly aggressive British raiders. The Royal Navy decided to prevent these troop convoys from reaching Illyria and sought to break French hegemony in the region, resulting in a six-year naval campaign.

The campaign was not uniform in approach; British and French forces were limited by the dictates of the wider Mediterranean and global conflict, and consequently ship numbers fluctuated. Although numerous commanders held commands in the region, the two most important personalities were those of William Hoste and Bernard Dubourdieu, whose exploits were celebrated in their respective national newspapers during 1810 and 1811. The campaign between the two officers reached a climax at the Battle of Lissa in March 1811, when Dubourdieu was killed and his squadron defeated by Hoste in a celebrated action.

The events of 1811 gave the British dominance in the Adriatic for the remainder of the war. British and Greek expeditionary forces steadily captured fortified French islands and their raiding parties inflicted havoc on trade across the region. As a result, French plans against the Ottoman Empire were cancelled, La Grande Armée turning towards Russia. British forces continued operations until the advancing armies of the Sixth Coalition drove the French from the shores of the Adriatic in early 1814, British troops and marines assisting in the capture of several important French cities, including Fiume (Rijeka) and Trieste.

Background There had been a French presence in the Adriatic Sea since the Treaty of Campo Formio during the French Revolutionary War. Campo Formio marked the end of the War of the First Coalition in 1797 and confirmed the demise of the independent Republic of Venice and the division of its territory between the French Republic and the Austrian Empire.Chandler p. 78 One of France's gains from this division were the seven Ionian Islands that controlled the entrance to the Adriatic. These French outposts in the Eastern Mediterranean were considered a threat by both the Russian and the Ottoman Empires and in 1798 a united Russo-Ottoman force attacked the massively fortified French citadel on Corfu, which fell the following year after a four-month siege. The victors took possession of the islands and from them created the Septinsular Republic, nominally Ottoman, practically independent and guaranteed by the Russian Navy.

On mainland Europe, the rise of Napoleon Bonaparte as the ruler of the new French Empire resulted in a new conflict, the War of the Third Coalition in 1805, which ended disastrously for the Austrian and Russian allied armies at the Battle of Austerlitz. The treaties that ended the war created two French client monarchies in Italy, the Kingdom of Italy and the Kingdom of Naples, and French troops were left holding substantial parts of the Eastern coastline of the Adriatic in Dalmatia.Chandler p. 348 These holdings significantly increased French naval interest in the Adriatic, which was well supplied with excellent ports and shipbuilding facilities, particularly at Venice.

The Russian garrison on Corfu, augmented with a powerful naval squadron, effectively blocked French use of the Adriatic by sealing the entrance through the Straits of Otranto. French military concerns were also directed further north at this time, resulting in the War of the Fourth Coalition during 1806 and 1807 that saw Napoleon's armies overrun Prussia and force the Russians to sign the Treaty of Tilsit on 7 July 1807.Chandler p. 163 One of the minor clauses of this treaty transferred the Ionian Islands back into French hands, the Russians withdrawing completely from the Adriatic.Adkins, p. 209 This withdrawal supported a hidden clause in the treaty that guaranteed French support in the continuing Russian war with the Ottomans in the Balkans.Chandler p. 441

Campaign Opening exchanges As the Russians withdrew, the French immediately despatched garrisons to the Ionian Islands, rapidly amassing over 7,400 French and Neapolitan troops on Corfu alone.Gardiner, p. 153 This effectively turned the Adriatic into a sheltered French sea from which they could be free to despatch raiders against British convoys, colonies and Royal Navy blockade squadrons, which had controlled the Mediterranean since the Battle of Trafalgar two years earlier.Gardiner, p. 9 To facilitate this, the French Navy placed significant orders at the Venetian naval yards, intending to build forces in the region with locally produced and crewed vessels.James, Vol. 6, p. 44

The Royal Navy's Mediterranean Fleet responded rapidly to this threat, and in November 1807 the fourth rate ship HMS Glatton and several smaller craft were blockading Corfu, seizing several French and Italian reinforcement convoys.James, Vol. 4, p. 342 Encouraged by the success of the blockade, small British raiders began entering the Adriatic independently, to prey on French convoys along the Italian coast. One of the first British operations in the region was the seizure of the small Dalmatian Island of Lissa, for use as a safe harbour deep in nominally French-controlled waters. The largely uninhabited island was rapidly developed into an effective naval base with the construction of a town and harbour at Port St. George.Henderson, p. 112 During 1807, British ships stationed in the Adriatic were relatively small and their impact was consequently minor. British raiders also limited their attacks on the Illyrian coast to purely military objectives in order to maintain the support of the local population, who supplied the British cruisers with food, water and naval stores. The French Mediterranean Fleet, led by Admiral Ganteaume made a foray to Corfu in February 1808 that the British blockading squadron was powerless to stop, but this was the only attempt by the French to send ships of the line to the region and the fleet had returned to Toulon by mid-March.Gardiner, p. 19

The first major British deployment into the Adriatic came in May 1808, when the frigate HMS Unite under Captain Patrick Campbell arrived off Venice. During May, Campbell severely disrupted French and Italian shipping off the busiest Adriatic seaport and captured three ships sent against him by the Italian Navy.James, Vol. 5, p. 52 The French response to these depredations was to despatch the small frigate Var to Venice, an action which had little effect on British operations. British activity in the Adriatic was however curtailed during the year by the British war with the Ottoman Empire, which absorbed the scant British naval resources in the Eastern Mediterranean.Woodman, p. 247James, Vol. 5, p. 57

Invasions of the Ionian Islands

The British presence in the Adriatic was greatly strengthened in 1809 with the arrival of the frigates HMS Amphion under William Hoste and HMS Belle Poule under James Brisbane. These reinforcements made an immediate impact with a series of raids in the Dalmatian and Ionian islands.James, Vol. 5, pp. 152–153 In February Belle Poule captured the Var off Valona; the French responded by despatching the frigates Danaé and Flore from Toulon.Gardiner, p. 154 HMS Topaze attacked these frigates as they arrived, but they were able to reach Corfu before sailing north to augment French defences in the Adriatic.James, Vol. 5, pp. 171–173

Throughout the year British attacks intensified, driven by Hoste's Amphion operating from Lissa. Raids on the Italian coastline seized dozens of coastal merchant vessels and gunboats while parties of marines and sailors landed at coastal towns, driving off the defenders and blowing up the fortifications before returning to their ships.James, Vol. 5, pp. 171–178 These successes in the face of negligible French opposition encouraged the British commander in the Mediterranean, Admiral Cuthbert Collingwood, to detail a force specifically to eliminate the French garrisons on the Ionian Islands. This expedition, led at sea by Brigadier-General John Oswald from HMS Warrior succeeded in landing on the island of Cefalonia on 1 October and forcing the Neapolitan garrison to surrender within hours.James, Vol. 5, p. 146 Within days the neighbouring islands of Zante and Ithaca had also surrendered and the detached frigate HMS Spartan under Jahleel Brenton effected a successful invasion of Cerigo shortly afterwards.Brenton, Sir Jahleel, Oxford Dictionary of National Biography, P. K. Crimmin, (subscription required), Retrieved 18 June 2008

These islands were defended by small garrisons, with a few dozen regular French soldiers and larger numbers of men of the Albanian Regiment(400 on Zante, 145 on Cefalonia, 46 on Ithaca, and 27 on Cerigo) on each island. These forces were completely inadequate to offer anything but a token resistance; the captured men were transferred to Italy as prisoners of war, but more than a few of the Albanian Regiment's men simply scattered into the countryside and resumed their traditional guerrilla habits. Most of these escapees, as well as those taken prisoner, were soon induced to enter British service in what eventually became the 1st Regiment Greek Light Infantry. Over 70% of the Albanian Regiment's men on the four islands switched to the British, including most of the officers. The 1st Regiment Greek Light Infantry, initially under Richard Church and later under Robert Oswald (brother of John), soon attracted many Greek military leaders who would later play a crucial role in the Greek War of Independence, most notably Theodoros Kolokotronis.

Troop withdrawals late in 1809 delayed any further invasions until March 1810, when Collingwood's temporary successor Thomas Byam Martin detached a squadron of the Mediterranean Fleet for an operation against Santa Maura. Landings were effected on 22 March, and the island surrendered on 16 April after an eight-day siege of the principal fortress, the attackers considerably aided by the desertion of the garrison's native Greek troops to the Greek volunteers fighting on the British side.Gardiner, p. 155 Along with a 2nd Regiment raised in 1813, the Greek units took part in the capture of Paxoi and Parga and the Allied capture of Genoa in 1814.

French reinforcements