On his return to England he was appointed to the Salisbury with Commodore Elliot, then going out as governor of Newfoundland. He was afterwards, in 1790, Elliot's signal lieutenant in the Barfleur, and on 12 Nov. was promoted to the command of the Daphne of 20 guns, for a passage to the West Indies, when he was transferred to the Cygnet sloop, which he brought home in December 1792. He was immediately afterwards appointed to the Spitfire of 20 guns, in which he put to sea on 12 Feb. 1793; and on the 13th fell in with and captured the Afrique, a French privateer, the first prize brought in in that war. He continued cruising with good success; and on 24 June 1793 was posted to the Narcissus frigate, from which, in October, he was moved to the Hind. In the following spring he was sent out to the Mediterranean with convoy, returning a few months later. This homeward convoy numbered 157 ships, the charge of which, by the accidents of the voyage, fell altogether on Durham. He had the good fortune to bring them all safely into the Downs, a service which the admiralty, acting on the recommendation forwarded from Lloyd's, acknowledged by appointing him (30 Oct. 1794) to the Anson of 46 guns, one of the largest frigates then in the navy. He commanded her for the next six years, during which time he was present at the action off Isle Groix and Lorient, 23 June 1795; was with Sir John Borlase Warren [q. v.] in his expedition to Quiberon Bay, in July 1795, and again on the coast of Ireland in September and October 1798, taking part in the defeat and capture of the French squadron off Tory Island on 12 Oct. (James, Naval History, (1860), ii. 140), a service for which he, together with the other captains present, received the thanks of parliament and a gold medal. In February 1801 Durham was moved into the Endymion of 40 guns, which was paid off at the peace. In April 1803 he was appointed to the Windsor Castle, but was presently moved into the Defiance of 74 guns, in which he took part in Calder's action off Cape Finisterre, 22 July 1805 [see Calder, Sir Robert]. The ship was then sent home to be refitted, but was hurried out to join Nelson off Cadiz. When Calder was ordered home for his trial, he was permitted to name such captains as he desired for witnesses, who thereupon received leave to accompany him to England [cf. Brown, William, d. 1814)]. Durham was one of those so selected, but finding that his going home was optional, he decided to stay. He had thus his share in the glories of Trafalgar, where he was slightly wounded; and being ordered home directly afterwards, arrived in England in time to give evidence on Calder's court-martial. He was next appointed to the Renown, which during 1806 formed part of the Channel fleet, and for a short time carried Lord St. Vincent's flag. Afterwards she was sent to join Collingwood in the Mediterranean, and continued there till 1810, during the latter part of which period Durham wore a broad pennant, and on 26 Oct. 1809 was engaged, in company with Rear-admiral Martin, in the destruction of two French ships, near Cette [see Collingwood, Cuthbert, Lord].
On 31 July 1810 he was promoted to be a rear-admiral. During 1811 he commanded a squadron in the North Sea, and had struck his flag only a few days when he was ordered to go to Portsmouth, take command of such ships as he chose, and sail at once in quest of a French squadron that had put to sea from Lorient. The cruise was but a short one, for the French returned to port, and Durham, bringing his ships back to Portsmouth, struck his flag. He next had command of a squadron in Basque Roads, and in December 1813 was sent out as commander-in-chief of the Leeward Islands station, with his flag in the Venerable. On the outward voyage he fell in with and cleverly captured two large French frigates, Alcmène and Iphigénie, on 16 and 20 Jan. 1814. Afterwards he cleared the West Indies of American cruisers; and in June and August 1815 co-operated in the reduction of Martinique and Guadeloupe, at which place the last French flag was struck to Durham, as the first had been. The following year he returned to England. On 2 Jan. 1815 he had been nominated a K.C.B.; he was now created a knight grand cross of the order of Military Merit of France, the only English officer, it is said, who received that distinction. On 12 Aug. 1819 he was promoted to be vice-admiral, on 22 July 1830 to be admiral, and on 17 Nov. 1830 was made a G.C.B. He was M.P. for Queenborough in 1830 and for Devizes 1834–6. From March 1836 to April 1839 he was commander-in-chief at Portsmouth. He commanded a squadron off Brighton on Queen Victoria's visit in 1837.
He married in 1799 the Lady Charlotte Matilda Bruce, daughter of the Earl of Elgin, and, secondly, in 1817 Anne Isabella, only daughter and heiress of Sir John Henderson, bart., of Fordel in Fife. On the occasion of this marriage he took the additional name of Henderson, and afterwards, on succeeding, by the death of his brother in 1840, to the Polton estate, took also the name of Calderwood. Lady Durham died suddenly towards the close of 1844. Shortly after
