Thomas DesBrisay was born in 1733 in Dublin (Republic of Ireland) and was the son of Theophilus DesBrisay and Magdalene de Vergese d'Aubussargues and in 1753 he married Ellen Landers (Landen) and they had 16 children.
Thomas DesBrisay was appointed an ensign in the 35th Foot (Donegall's) at the age of ten. He attained the rank of Captain in the Royal Irish Artillery on February 7, 1760. This career was terminated when, on July 31, 1769 he was commissioned Lieutenant Governor, Secretary and Registrar of St. John's (Prince Edward) Island. Ten years would lapse before he took up the appointment. Having acquired land on the Island, he busied himself for a few years with attempts to recruit settlers in Ireland. In 1773, however, the British government unwilling to encourage emigration, expressly forbad him to continue his efforts.
On July 8, 1771, apparently believing that DesBrisay was soon to arrive, Governor Walter Patterson had appointed DesBrisay a Justice of the Peace for Queens County. Three years later Patterson was to describe the absentee Lieutenant Governor as "very unfit to hold any offices under His Majesty." He charged that DesBrisay had attempted to interfere in the proper allocation of Colonial funds; moreover, he had mortgaged his properties and, without discharging the mortgages, sold parcels of land to prospective settlers who were subsequently ruined by the expense of a voyage from the British Isles and the loss of their purchase money, the deeds they had received from DesBrisay being of no effect. DesBrisay was nevertheless retained as Lieutenant Governor and in the summer of 1779 was ordered by the Secretary of State for the American Colonies to take up his appointment.
Because Patterson was absent from the colony when DesBrisay arrived on October 10, 1779 DesBrisay, as Senior Officer, assumed command. During a nine month period he granted some 400 crown lots in Charlottetown Royalty, apportioning 58 town lots and 58 pasture lots to himself and members of his family. The British Government considered his behavior sufficient grounds for dismissal but acquiesced in Patterson's proposal that instead DesBrisay and the others who had acquired the lots should be made to surrender the bulk of them to the Crown in open court. DesBrisay's role in this affair no doubt explains why the remarkable number of requests for preferment that he addressed to London went unanswered. His hatred for Patterson, who had exposed him, must have intensified in 1781 when the governor claimed for himself a large portion of the land sold in November because proprietors' failure to pay quitrents.
With the organization of the colonial administration in 1784 the office of Governor of St. John's (Prince Edward) Island was eliminated. Patterson, as a consequence, became Lieutenant Governor, and DesBrisay lost both his post and his seat on the Council. He was, however, appointed Clerk of the Council on January 22, 1785. Unwilling to "sit, as clerk, at the foot of a Board where I was appointed by His Majesty President," he was permitted to exercise his duties as Deputy, and Charles Stewart was chosen for the position. The presence of a non-member Clerk at the Council meetings, a custom which was continued until DesBrisay's death, represented a departure from British tradition, and the Upper House of Prince Edward Island became unique in this respect. In 1789 DesBrisay was appointed to the Council by Lieutenant Governor Edmund Fanning.
Injured pride also figured in DesBrisay's resentment at Phillips Callbeck's being recommended in 1781 to command a company for the defence of the colony in preference to him, as former Chief Justice Peter Stewart's claim to precedence over him at Council's meetings in 1801, and William Townshend's being appointed temporary Commander-In-Chief of the colony in 1813 to the exclusion of his own claim as senior councillor. As late as 1818, when DesBrisay was described as being "infirm and aged even to superannuation," Lieutenant Governor Charles Douglass Smith remarked that "it would hurt the old man's feelings much ever to be removed from the Council."
Because of failing eyesight, DesBrisay had his grandson, Theophilus, assist him in the performance of the duties of Secretary and Registrar for some 15 years before his death. Thomas DesBrisay died in Prince Edward Island on September 25, 1819 at the age of 86.
Source: Dictionary of Canadian Biography Online