In 1792, Smith's younger brother,
John, was appointed to the British embassy to the
Ottoman court in
Constantinople. Smith obtained permission to travel to the
Ottoman Empire. While there, Revolutionary France declared war on Britain on February 1793. Smith recruited some British seamen and sailed to join the British fleet under Admiral Lord
Hood which had occupied the French Navy's principal Mediterranean port of
Toulon at the invitation of the French Royalist forces. By Smith's arrival in December 1793, the Revolutionary forces, including a colonel of artillery,
Napoleon Bonaparte, had surrounded the port and were attacking it. The British and their allies had insufficient soldiers to mount an effective defence and so the port was evacuated. Smith, serving as a volunteer with no command, was given the task of burning as many French ships and stores as possible before the harbour could be captured. Despite his efforts, lack of support from the Spanish forces sent to help him left more than half of the French ships to be captured undamaged. Although Smith had destroyed more French ships than had the most successful fleet action to that date,
Nelson and
Collingwood, among others, blamed him for this failure to destroy all of the French fleet. On his return to London, Smith was given command of the
fifth-rate and in 1795 joined the
Western Squadron under Sir
John Borlase Warren. This squadron consisted of some of the most skilful and daring captains, including
Sir Edward Pellew. Smith fitted this pattern and on one occasion took his ship almost into the port of
Brest to observe the French fleet. In July 1795, Captain Smith, commanding the western frigate squadron in HMS
Diamond, occupied the
Îles Saint-Marcouf off the coast of
Normandy. He sacrificed two of his gun vessels, and , to provide materials and manpower for fortifying the islands and setting a temporary naval garrison. Further defences were constructed by Royal Engineers, and Royal Marines and Royal Artillery detachments were established. The islands served as a forward base for the blockade of
Le Havre, a launching point for intercepting coastal shipping, and as a transit point for French émigrés, and were held by the Royal Navy for nearly seven years. Smith specialised in inshore operations, and on 19 April 1796, he and his secretary
John Wesley Wright were captured while attempting to cut out a French ship in
Le Havre. Smith had taken the ship's boats into the harbour, but the wind died as they attempted to leave the harbour, and the French were able to recapture the ship with Smith and Wright aboard. Instead of being exchanged, as was the custom, Smith and Wright were taken to the
Temple prison in
Paris where Smith was to be charged with arson for his burning of the fleet at Toulon. As Smith had been on half pay at the time, the French considered that he was not an official combatant. Whilst in the Temple prison he commissioned a drawing of himself and his secretary
John Wesley Wright from the French artist
Philippe-Auguste Hennequin, which is now in the British Museum. Another drawing by Hennequin, depicting only Smith, is in the
Metropolitan Museum of Art. Smith was held in Paris for two years, despite a number of efforts to exchange him and frequent contacts with both French Royalists and British agents. Notably Captain
Jacques Bergeret, captured in April 1796 with the frigate
Virginie, was sent from England to Paris to negotiate his own exchange; when the Directoire refused, he returned to London. The French authorities threatened several times to try Smith for arson, but never followed through on the threats. Eventually in 1798 the Royalists, who pretended to be taking him to another prison, helped Smith and Wright to escape. The royalists brought the two Englishmen to Le Havre, where they boarded an open fishing boat and were picked up on 5 May by on patrol in the
English Channel, arriving in London on 8 May 1798. Bergeret was then released, the British government considering the prisoner exchange as completed. ==Service in the Mediterranean==