Britain was not unaware of French preparations at Toulon and along the Mediterranean coast, but despite sustained efforts by British agents in France the destination of the French fleet was unknown.
Egypt was not seriously considered by the British government: when Secretary of State for War Henry Dundas suggested it, he was urged by Foreign Secretary Lord Grenville to think "with a map in your hand, and with a calculation of distances."
Letters reached London and St. Vincent at the Tagus describing extensive preparations right along the French and Italian Mediterranean coastlines, but the distances between the base in the Tagus and Toulon prevented any sustained observation of French movements.
Urgent orders were sent from Lord Spencer at the Admiralty to Vice-Admiral Earl St. Vincent, commander of the British Mediterranean Fleet at the Tagus, to despatch a squadron to investigate under the command of Rear-Admiral Sir Horatio Nelson.
Nelson had returned to the fleet three days earlier at Lord Spencer's order, following recovery in Britain from the loss of an arm at the Battle of Santa Cruz de Tenerife in July 1797.

St. Vincent had already been preparing for an expedition to Toulon with Nelson in mind, and the rear-admiral departed the Tagus in his flagship HMS Vanguard on 2 May. St Vincent was overjoyed to be able to place Nelson in command of the mission, writing that "the arrival of Admiral Nelson has given me new life ... his presence in the Mediterranean is so very essential".
His preference for Nelson over the more senior admirals Sir William Parker and Sir John Orde provoked a storm of protest, which eventually culminated in Orde challenging St Vincent to a duel, and being subsequently ordered to return to Britain.
On 9 May Nelson collected the ships of the line HMS Alexander and HMS Orion under Captains Alexander Ball and Sir James Saumarez the frigates HMS Emerald and HMS Terpsichore under Captains Thomas Moutray Waller and William Hall Gage and the sloop HMS Bonne Citoyenne under Captain Robert Retalick at Gibraltar, and passed into the Mediterranean.
Despite leaving under cover of darkness, Nelson's departure was observed by Spanish forces at Cadiz, and the fort at Cape Carnero fired several shot, striking Alexander but inflicting negligible damage.

On 17 May Terpsichore captured the privateer La Pierre off Cape Sicié, and from the crew Nelson learned that Bonaparte's departure was imminent, although the destination was still unknown.
On 21 May, as his squadron reached the Îles d'Hyères near Toulon, they were struck by strong winds that snapped Vanguard's topmasts and brought the wreckage down onto the deck, killing two men.
Vanguard was left struggling in heavy seas, blown 75 nautical miles (139 km) southwards in one night.
So severe was the damage that Vanguard was almost wrecked on the Corsican coast on the following day and Nelson even ordered Captain Ball, who had managed to attach a towline to the flagship, to abandon him.
Ball refused the order and the British ships of the line rode out the storm together.
Although Alexander was able to tow Vanguard to San Pietro Island off Sardinia for repairs, the gale had forced the squadron's frigates to separate from the larger ships.

Thomas Waller on Emerald was divided from the other frigates, and his lookouts had observed Vanguard in its dismasted state at the height of the storm.
The other two frigates had reefed their sails and ridden out the storm together, Captain Gage turning towards the Spanish coast when the storm abated and on 29 May encountered HMS Alcmene under Captain George Johnstone Hope, which had been sent by St. Vincent to augment Nelson's force.
Two days later Hope's squadron encountered Emerald, which had captured two merchant ships, and together they sailed for the prearranged rendezvous point 60 miles (97 km) off Cape St. Sebastian near Barcelona.
Hope ordered Terpsichore and Bonne Citoyenne to cruise off Sardinia and on 3 June encountered the brig HMS Mutine under Captain Thomas Hardy, the scout of a fleet sent by Earl St. Vincent that was a
Britain was not unaware of French preparations at Toulon and along the Mediterranean coast, but despite sustained efforts by British agents in France the destination of the French fleet was unknown. Egypt was not seriously considered by the British government: when Secretary of State for War Henry Dundas suggested it, he was urged by Foreign Secretary Lord Grenville to think "with a map in your hand, and with a calculation of distances." Letters reached London and St. Vincent at the Tagus describing extensive preparations right along the French and Italian Mediterranean coastlines, but the distances between the base in the Tagus and Toulon prevented any sustained observation of French movements. Urgent orders were sent from Lord Spencer at the Admiralty to Vice-Admiral Earl St. Vincent, commander of the British Mediterranean Fleet at the Tagus, to despatch a squadron to investigate under the command of Rear-Admiral Sir Horatio Nelson. Nelson had returned to the fleet three days earlier at Lord Spencer's order, following recovery in Britain from the loss of an arm at the Battle of Santa Cruz de Tenerife in July 1797.
St. Vincent had already been preparing for an expedition to Toulon with Nelson in mind, and the rear-admiral departed the Tagus in his flagship HMS Vanguard on 2 May. St Vincent was overjoyed to be able to place Nelson in command of the mission, writing that "the arrival of Admiral Nelson has given me new life ... his presence in the Mediterranean is so very essential". His preference for Nelson over the more senior admirals Sir William Parker and Sir John Orde provoked a storm of protest, which eventually culminated in Orde challenging St Vincent to a duel, and being subsequently ordered to return to Britain. On 9 May Nelson collected the ships of the line HMS Alexander and HMS Orion under Captains Alexander Ball and Sir James Saumarez the frigates HMS Emerald and HMS Terpsichore under Captains Thomas Moutray Waller and William Hall Gage and the sloop HMS Bonne Citoyenne under Captain Robert Retalick at Gibraltar, and passed into the Mediterranean. Despite leaving under cover of darkness, Nelson's departure was observed by Spanish forces at Cadiz, and the fort at Cape Carnero fired several shot, striking Alexander but inflicting negligible damage.
On 17 May Terpsichore captured the privateer La Pierre off Cape Sicié, and from the crew Nelson learned that Bonaparte's departure was imminent, although the destination was still unknown. On 21 May, as his squadron reached the Îles d'Hyères near Toulon, they were struck by strong winds that snapped Vanguard's topmasts and brought the wreckage down onto the deck, killing two men. Vanguard was left struggling in heavy seas, blown 75 nautical miles (139 km) southwards in one night. So severe was the damage that Vanguard was almost wrecked on the Corsican coast on the following day and Nelson even ordered Captain Ball, who had managed to attach a towline to the flagship, to abandon him. Ball refused the order and the British ships of the line rode out the storm together. Although Alexander was able to tow Vanguard to San Pietro Island off Sardinia for repairs, the gale had forced the squadron's frigates to separate from the larger ships.
Thomas Waller on Emerald was divided from the other frigates, and his lookouts had observed Vanguard in its dismasted state at the height of the storm. The other two frigates had reefed their sails and ridden out the storm together, Captain Gage turning towards the Spanish coast when the storm abated and on 29 May encountered HMS Alcmene under Captain George Johnstone Hope, which had been sent by St. Vincent to augment Nelson's force. Two days later Hope's squadron encountered Emerald, which had captured two merchant ships, and together they sailed for the prearranged rendezvous point 60 miles (97 km) off Cape St. Sebastian near Barcelona. Hope ordered Terpsichore and Bonne Citoyenne to cruise off Sardinia and on 3 June encountered the brig HMS Mutine under Captain Thomas Hardy, the scout of a fleet sent by Earl St. Vincent that was a
Mediterranean campaign of 1798