Dabzac, Henry Joseph (1737–90), academic, was born in Minorca, son of Henry d'Abzac (1677–1750) and his wife (m. 1711 in Dublin) Magdalen, daughter of Capt. D'Artoux. Henry d'Abzac, naturalised as a subject of the crown in Ireland, was the son of Marc Dabzac by Jane (b. 1703 at Limeult, Guienne, France); he bought a lieutenancy in Gen. Sir William Stuart's regiment in 1704–5, and served in Portugal, later becoming lieutenant-colonel in the Royal Irish Regiment of Foot. By his will (proved June 1750) Henry Joseph Dabzac was to receive £1,500 at age 25, and ultimately £3,000. The family had its origins in Périgord, as Dabzac learned when he made enquiries of his ancestry from sundry family members and prepared a short account in 1767: ‘We all came to Ireland in August 1745, my father having sold his commission . . . in Dublin’.
Dabzac was sent to school with Dr Dunkin in Dublin, but Dunkin removed to Portorara Royal School, Enniskillen, Co. Fermanagh, as master in 1746. Dabzac was subsequently under the Rev. John Lamy at Raphoe from April 1752 to 1753. He entered TCD (1753), graduated BA (1757), and became a fellow (1760–75) and a senior fellow (1775–90). He was Donegal lecturer in 1764 and gained his BD (1767) and DD (1772). He was Archbishop King's lecturer (1773, 1779), and proceeded MA in 1780. He served as regius professor of Greek (1775–8) and professor of modern history (1778–90) and concurrently was regius professor of laws (1779–82). He married (March 1774) Catherine, daughter of Col. Pigou, and they had twelve children (of whom four died in infancy), for which he received a dispensation from Provost John Hely-Hutchinson (qv), who in 1775 ‘secured support [for his parliamentary ambitions] of two senior fellows . . . and Dr Dabzac, each clandestinely married’ (quoted in Kinane & Walsh), so as to retain his fellowship and professorial posts. Patrick Duigenan (qv), in his Lachrymae academicae, called him ‘a creature of Hely-Hutchinson’ (quoted in Luce (1992), 57). He was friendly with younger men at Trinity such as Henry Ussher (qv), the astronomer, Richard Lovell Edgeworth (qv), the engineer and father of Maria Edgeworth (qv), and Daniel Beaufort (qv), cartographer (also of huguenot descent), who became librarian of the new Royal Irish Academy in 1787. Dabzac was librarian at Trinity from 1785 until his death, a post usually designated to one of the more junior fellows, but his acquaintance with the library was perhaps more effective than that of others in the post in that he had previously served as assistant librarian in 1768. His assistant for the period 1785–90 was John Barnett. Dabzac died 12 May 1790 and was buried in the huguenot cemetery at Merrion Row, where the family graves extend down to the burial of his daughter Anne Vesey in 1861. His will was proved May 1790. His son Henry died from wounds received at Albuera in 1811; his widow died in 1818. An oval bust portrait showing Henry Dabzac wearing a gown with bands and white stock is in TCD.