Sir John Mordaunt was a British soldier and Whig politician, the son of Lieutenant-General Harry Mordaunt and Margaret Spencer. He was best known for his command of the Raid on Rochefort which ended in failure and his subsequent court-martial. Cleared on a technicality, he was nonetheless barred from holding further military command.
On the outbreak of the Seven Years' War in 1756, Mordaunt was placed in charge of training troops at Blandford. The next year, he was appointed to command an amphibious assault on the French port of Rochefort. The immediate objective was to destroy France's Royal Dockyard at the port. A secondary objective was to highlight Britain's capacity to strike at the French mainland, and force France to withdraw troops from other conflicts to defend its western coastline. The plan was championed at the highest levels, including by British Prime Minister William Pitt. Mordaunt was placed in overall Army command for the assault, supported by Major-General Henry Seymour Conway and Colonel Edward Cornwallis. Royal navy command was vested in Admirals The naval commanders, Sir Edward Hawke and Sir Charles Knowles. The force of 31 warships and 49 transports carrying 10 battalions of soldiers set sail on 6 September 1757, and captured the Île d'Aix on 21 September. However, they now discovered that shallow water would prevent the ships from approaching closer than a mile and a half from shore, requiring a long and hazardous landing by boats. An attack was planned on the basis of a report by Colonel James Wolfe, who had gone ashore at Rochefort with a scouting party and concluded that the French garrison as too weak to prevent the landing. Wolfe urged Mordaunt into action, offering to capture the town himself if given just 500 men. Despite the report, Mordaunt remained uncertain of victory. On 25 September he called a council of war aboard, where debate included the prospect of French reinforcements and the possibility that the French might better fortify the town before the British troops could arrive. After two days' discussion, Mordaunt and Conway concluded that assaulting Rochefort was "neither advisable nor practical". A second council, called on 28 September aboard, reversed this decision and decided on a night attack upon the forts at the mouth of the River Charente, with the first embarkation to be led by Mordaunt in person. However, Mordaunt remained equivocal, and the attack did not proceed. Frustrated at the Army's refusal to act, Admiral Hawke declared that as the Army had no willingness to make an assault, the fleet would return to England. The expedition set sail on 29 September and reached Portsmouth on 6 October. Pitt was furious at the failure of the expedition, and at the expenditure of more than £1,000,000 without result. A board of inquiry was convened under the auspices of Charles Spencer, 3rd Duke of Marlborough, George Germain, 1st Viscount Sackville and John Waldegrave, 3rd Earl Waldegrave. In keeping with Wolfe's report to Mordaunt, the board found that "it does not appear to us that there were then, or at any time afterwards either a Body of Troops or Batteries on the Shore sufficient to have prevented the attempting a Descent" and that it did not believe the defences of Rochefort could have been sufficiently improved so as to repel an assault. In the wake of the inquiry, Mordaunt was tried by court-martial in December. Mordaunt's defence centred on the technicality that his instructions for the expedition did not include an absolute requirement to make a landing. He was acquitted of disobedience, but George II removed Mordaunt, Conway and Cornwallis from the staff in July 1758.
Later career
Mordaunt retained his commission, but having earned the King's displeasure after Rochefort, he never again held a senior field command. He was promoted general in 1770, and was Governor of Berwick-upon-Tweed from 1778 until 1780. He died in his home near Southampton in 1780. He never married and left no children.
