By March 1800 Valletta, the Maltese capital, had been under siege for eighteen months and food supplies were severely depleted, a problem exacerbated by the interception and defeat of a French replenishment convoy in mid-February.

Pausing at Malta on 9 June, Bonaparte landed soldiers and seized the island leaving a sizeable French garrison at Valletta under General Claude-Henri Belgrand de Vaubois while the rest of the fleet continued on to Alexandria.

[4] By the start of October, British and Portuguese troops had supplemented the Maltese irregulars, while a naval squadron watched Valletta harbour, to prevent any French effort to resupply and reinforce the garrison.

[7] Without Perrée's supplies, the garrison faced continued food shortages, and by March Vaubois and Villeneuve decided to send an urgent request for support to France.

For this operation they chose the 80-gun Guillaume Tell under Captain Saulnier, partly because the condition and size of the ship enabled Vaubois to embark over 900 men aboard, many of whom were sick or wounded.

[10] At 23:00 on 30 March, with a strong wind from the south, Guillaume Tell sailed from Valletta, Decrès hoping to use the cover of darkness to escape the British blockade.

[8] At 23:55, Blackwood's lookouts spotted Guillaume Tell and the captain gave chase, ordering the brig HMS Minorca under Commander George Miller to convey the message to Dixon, whose ships were just visible in the distance.

[15] By 06:30 the badly outnumbered French ship had lost both its main and mizen masts, Foudroyant returning to the battle in time to collapse the foremast by 08:00.

[15] Both Foudroyant and Lion were too battered to provide an effective tow to the dismasted French ship, and as a result Penelope was left to bring the shattered Guillaume Tell into Syracuse on Sicily.

The British officers were praised for the capture of Guillaume Tell, the last surviving French ship of the line to escape the Battle of the Nile: Nelson, who by his absence had "missed what would indeed have been the crowning glory to his Mediterranean career", wrote to Berry that "Your conduct and character in the late glorious occasion stamps your fame beyond the reach of envy.

"[21] Despite Nelson's praise however, Berry in particular came in for subsequent criticism, especially from the historian William James, who wrote in his 1827 history of the conflict that: "Had the Foudroyant, single-handed, met the Guillaume-Tell, the combat would have been between two of the most powerful ships that had ever so met; and, although the Foudroyant's slight inferiority of force, being chiefly in number of men, was not that of which a British captain would complain, still the chances were equal, that the Guillaume-Tell, so gallantly manned, and so ably commanded, came off the conqueror.

"James instead attributed most of the praise for the victory to Blackwood and Dixon, whose ships were heavily outmatched by Guillaume Tell, but who successfully pressed their attacks with the intention of delaying the French retreat.

Despite Vaubois' defiance, the garrison was rapidly starving, and although the French commander resisted until 4 September, he was eventually forced to surrender Valletta and all of its military equipment to the British.