Dictionary of National Biography, 1885-1900/Montresor, James Gabriel
MONTRESOR, JAMES GABRIEL (1702–1776), director and colonel royal engineers, son and heir of James Gabriel Le Tresor, esq., of Thurland Hall, Nottinghamshire, and Nanon, daughter of Colonel de Hauteville of Normandy, but in the English service, was born at Fort William, Scotland, 19 Nov. 1702. His father, descended from William Le Tresor, Viscompte de Conde sur Mogleaux, was born at Caen, Normandy, and naturalised in England during the reign of William III. He was major of the 21st foot, and lieutenant-governor of Fort William, Scotland, where he died 29 Jan. 1724, aged 56.
Montresor was a matross at Mahon, Minorca, in 1727, with pay at Is. per diem. The following year he was at Gibraltar, where he was a bombardier at Is. 8d. per diem, and distinguished himself at the siege. He was given a commission as practitioner-engineer on 2 Oct. 1731, and on 5 April 1732 was gazetted an ensign in the 14th foot. In August he went to England on four months' leave of absence, but returned to Gibraltar, where his skill as a draughtsman and ability in the execution of works won him some distinction. On 23 July 1737 he was promoted lieutenant in the 14th foot, on 7 Feb. 1739 sub-engineer, and on 3 July 1742 engineer extraordinary. The following year he was sent to Port Mahon as engineer in ordinary, his commission dating from 5 Oct. 1743. He carried out his new charge with credit until 1747, when he was appointed on 2 Jan. chief engineer at Gibraltar, with pay of 20s. per diem, in succession to Skinner, required for duty in Scotland. As chief engineer he greatly improved the defences, and some thirty drawings in the war office testify to the numerous services he carried out between 1747 and 1754. On 17 Dec. 1752 he was promoted sub-director. In June 1754 he returned to England, and on 9 Nov. was appointed chief engineer of the expedition to North America under Major-general Braddock. He preceded the army in June 1755 to prepare roads for Braddock's advance from Alexandria in Virginia, over the Alleghany mountains, through a difficult and unexplored country. He was present on 9 July at the disastrous battle of Du Quesne, where he was wounded and lost all his baggage and the engineer stores. He made his way with the retreating army to Fort Cumberland, and thence on 2 Aug. to Philadelphia, and finally, under orders from General Shirley, Braddock's successor, he went to Albany, where he remained for seven months, preparing plans and projects for the ensuing campaign.
In 1756 Montresor surveyed Lake Champlain and the military positions in its vicinity, and produced a map of part of the lake, showing the forts of Edward and William and other defences. He designed in 1756 a typical field redoubt for use against the Indians, which was ordered to be generally adopted. By General Shirley's directions he went to Lake George, and he reported so unfavourably on a fort recently constructed that he was ordered to reconstruct it. Montresor was much consulted by Shirley, and attended all his councils of war at Albany. On 14 May 1757 he was gazetted major in the army, and on 4 Jan. 1758 he was promoted director and lieutenant-colonel.
In 1758 Montresor was sent to Annapolis, Nova Scotia, to report on the defences, but when the campaign opened he rejoined the army for service in the lake country. In 1759 he accompanied the army of General Amherst, and as chief engineer distinguished himself by his fertility of resource and by the work he accomplished with insufficient means and materials collected in the emergency. In June he went to Lake George, put the fieldfort there in repair, and in concert with the general selected a site for a permanent fort. He traced out the defence works, and remained on the spot to superintend its erection. The work was well advanced in 1760, with accommodation for six hundred men, and called Fort George. While constructing the fort Montresor was in command of the troops and outposts of the line of communications between Albany and Lake George, a command he held till his return to England in the spring of 1760.
The fatigues of the campaigns had told upon his health, and although appointed on 1 Oct. 1760 chief engineer of the expedition against Belle Isle, he was too ill to go. He was on the sick list for the next two years, travelling about in search of health. On 3 Feb. 1762 he resigned his commission in the 14th foot. From 1763 to 1765 he was employed in designing and superintending the erection of the new powder magazines at Purfleet in place of those at Greenwich, which, by an act of parliament of 1761, were ordered to be destroyed. In 1769 he was chief engineer at Chatham. On 25 May 1772 he was promoted colonel. He died on 6 Jan. 1776 at New Gardens, Teynham, Kent. He was buried at Teynham, and there is a tablet on the north wall of the chancel of the church to his memory and to that of his third wife and her first husband. The epitaph gives Montresor's age at his death as sixty-six; it should be seventy-three.
Montresor married, first, at Gibraltar, on 11 June 1735, Mary, daughter of Robert Haswell, esq. (she died 5 March 1761); secondly, on 25 Aug. 1766, Henrietta, daughter of Henry Fielding, esq.; and thirdly, Frances, daughter of H. Nicholls, esq., and relict of William Kemp, esq., of New Gardens, Teynham. By his first marriage he had several sons: John [q. v.], who became chief engineer in America; James, a lieutenant in the navy, lost in the frigate Aurora; and Henry, who died of wounds received at the siege of Trichinopoly.
The following plans drawn by Montresor are in the British Museum: (1) A drawn plan of the city and peninsula of Gibraltar with the Spanish lines, in five sheets, 1742; (2) A drawn plan of the isthmus, city, and fortifications of Gibraltar, with elevation and sections of the principal public buildings, profiles through the two extremities of the rock and fort built by the Spaniards, with several additional designs for better defending and securing the place, eight sheets, 1753. The following plans, lately in the war office, are now in the archives of the Dominion of Canada : (1) Plan of part of river of St. Lawrence from Montreal to Isle of Quesny; (2) Part of Lake Champlain, showing Forts Edward, William, &c., 1756.
The following plans are in the war office: (1) Description and map of Gibraltar, coast of Spain and Barbary, 1748; (2) Particular survey of the city of Gibraltar, showing government property, 1753. Also twenty-six plans of various parts of the works of defence, with sections of the fortress of Gibraltar, and of the barracks and also of the Spanish lines and forts, dating from 1747 to 1752.
[Royal Engineers' Corps Records; War Office and Board of Ordnance Records; Burke's Landed Gentry.]