An English visitor to Gibraltar in 1830 found the town so squalid that he thought the only thing to do was to pull it down. Poor sanitation made it even unhealthier than Valletta.
In the same year an alleged insult to the French consul in Algiers by one of the Dey's officials provided the British with a suitable pretext.
An expedition was assembled in Toulon during early 1830 and on 25 May a force of 350 vessels and 35,000 troops set off for North Africa. A British naval patrol dashed from Malta to check on it. But the French had been careful that this expedition was in no sense a battle fleet, but rather a collection of troopships. The British did nothing to stop its progress and by 5 July the Dey capitulated to the French force put ashore.
A key Russo-Turkish understanding had for years been that in peacetime no foreign warship was allowed to pass through the Dardanelles Straits. Whoever controlled the Straits could bar any rival coming down from the north or entering from the south. That was what made Constantinople in the eyes of many then and later the first strategic position in the world.
But following the Treaty of Unkiar Skelessi (8 July 1833) when frustrated by lack of support by the British, the Sultan turned to Russia for support, the resulting Russian leverage now meant that her fleets would be able to dash into the Mediterranean and inflict punishment on an enemy, and get back to total safety before anybody could react. Unkiar Skelessi thus mortgaged the eastern Mediterranean to Russian power.
From the moment of this treaty's signature, Lord Palmerston, Foreign Secretary in the Whig government that followed the foundering of Wellington's Tory ministry, settled on the treaty's reversal as the touchstone of his foreign policy. The Sultan had to be weaned from Russia and provided with incontrovertible proof that Great Britain was "a safer and more acceptable shield" against the Egyptians.
A Navarino-like exercise in naval power was bound to be called for sooner or later. King William IV (the "Sailor King") had for some time been pressing his government to increase British warships into the region and after 1834 Palmerston added his weight.
The Mediterranean Fleet was progressively reinforced and kept in a constant state of readiness. It was in and out of Valletta harbour with unprecedented frequency.
Work got underway to improve and expand Malta's dockyard facilities. The numbers of British naval personnel rose sharply.
The island became a more important place for another reason. In the pre-telegraph age, the British Fleet in an emergency would be reduced to impotence if it had to await instructions from London before it could even begin to move. Speed and decisiveness were essential.
The British Government therefore reluctantly gave joint contingent powers - the "last trump of whist", as it was called - to Ambassador Ponsonby at Constantinople and the Commander-in-Chief of the Mediterranean Fleet in Valletta to send British warships rushing to the Dardanelles if necessity arose.
This meant that events of potentially immense cost to Britain - involving huge sums of money and perhaps many lives - might in effect be triggered, not from Downing Street, but from the Embassy in Constantinople and from the naval headquarters in South Street, Valletta. It was this political power inherent in British naval leadership in the Mediterranean which helped to set it apart for much of the 19th century.
On 24 June 1839 the Egyptians defeated the Ottomans at the Battle of Nezib. Almost simultaneously the Turkish fleet defected by sailing to Alexandria and on 1 July 1839 Sultan Mahmud II died. Turkey had lost a battle, an army, a fleet and a Sultan more or less simultaneously. It was a moment in which the configuration of power in the eastern Mediterranean hung in the balance.
When the crisis first erupted, the British fleet under Admiral Sir Robert Stopford and its French counterpart were both sent by their governments rushing towards the Dardanelles. The general expectation in the British squadron was that the joint Anglo-French force would smash their common Russian rival.
But then Palmerston did a U-turn mostly out of suspicion of the French and went into diplomatic harness with the Russians. France was left out on the sidelines.
Stopford's squadron, including Austrian and Turkish, as well as British warships, was meanwhile dispatched to the Syrian coast to carry out a naval attack against the Egyptian occupation. Palmerston was careful to defend this operation by saying it was conducted in the name of the new Sultan.
On 9 September 1840 Beirut was bombarded and Sidon shortly afterwards. Such a demonstration of the Royal Navy's ability to disrupt almost any military activity subject to British disapproval would be one of the defining features of its Mediterranean prestige.
The climax came when Stopford was ordered to reduce Acre, a resonant name in the ears of the British public because of its association with Napoleonic campaigns.
Eight ships of the line pounded the town during the afternoon of 3 November for three hours. Eventually the powder magazine in the fort exploded. The tremor was so great that even the British ships were shaken to their keels. Twelve hundred died under the rubble. A British eyewitness stated afterwards: "The town and walls (of Acre) present a mass of ruin beyond conception, but what place could withstand the fire of more than 400 cannons, directed with a precision and rapidity unknown in any former warfare?"
HMS Charlotte delivered 4,500 32-pound cannonballs. British losses were light: 18 killed and 41 wounded.
The reduction of Acre has been described as "the high water mark of naval gunnery during the age of sail". It served as a crushing example to those in Europe who doubted Britain's preparedness to act against those who threatened Mediterranean stability a l'anglaise. Acre left an indelible impression, and - along with the assault on Algiers in 1816 - was later to be quoted as a precedent for forceful naval action against the Crimean fortress of Sevastopol.
The ensuing settlement over the Straits marked Palmerston's greatest overseas triumph, just as Unkiar Skelessi had been his biggest defeat. It slotted into place a vital component of Britain's preponderance in the Mediterranean.
Henceforth Great Britain could to a large degree control entrance into and exit from the Mediterranean at both ends, that is, through the Straits of Gibraltar and at the Dardanelles (hence the common metaphor of a "British lake").
Malta provided a central base from which the Royal Navy could move quickly in any direction. Italy still remained subject to a friendly power in Austria. Spain had been at least partially "portugalised".
French dreams of Mediterranean revival had been scuppered in the East and carefully regulated in the West. This was "the last oriental attempt to found a power on the shores of the Mediterranean".
But the British maritime reach had its limits. Palmerston, despite his natural belligerence, was never interested in territorial gain and had a realistic grasp of diplomacy as the art of the possible.
Britain's Mediterranean mastery depended on its acceptability to others and on not pressing its claims too far. In pursuing this modus operandi the British did not make themselves loved in the Mediterranean or in Europe generally, but it made them respected and above all heeded in the things that really mattered to them.
By 1841, then, a durable equilibrium had come into being in the Mediterranean, incorporating a much more confident and stable British presence than in 1815. This presence was subtle and pervasive, underpinned by an expanding British trade with southern Europe.
It was policed from Gibraltar, Malta and (to a somewhat lesser extent) Corfu. These were no longer depots of fluctuating safety as they had still been at the end of the long wars against France, but rather imperial fortresses.
The established principle had emerged that the garrisons lodged in these strongpoints should not be less than 2,500 in Gibraltar, 3,000 in Malta and 3,000 in the Ionian Islands. In 1840 there were 9,000 regular British troops stationed in the Mediterranean or 20% of all British troops serving overseas.
These places were never quite as strategically indispensable or as impregnable as the British public supposed, but the imagery itself was influential in shaping conceptions of the Mediterranean and Britain's place in it.
(To be continued)