Joly, Jaspar Robert (1819–92), book collector, was born at Hollywood House, Brackagh, Clonbulloge, King's Co. (Offaly), on 26 May 1819, the eldest of three sons of Henry Edward Joly (1784–1852), a clergyman, and his wife Martha, daughter of Robert Revelle of Hartwill, Co. Wicklow. His paternal grandfather, Jean Jaspar Joly (1740–1823), was a native of Charneux in the duchy of Limburg, part of the Austrian Netherlands, who in 1768 became private secretary to Lord William Robert Fitzgerald (qv) and later became a protestant, settled in Ireland and acquired valuable property in Dublin. Jaspar Robert Joly was educated by his father, who was rector of Clonsast, King's Co., and at the age of thirteen entered TCD. After graduating BA (1837), he was called to the Irish bar (1841) but, though he later graduated LLB and LLD (1857) and was an authority on church law, he never practised. Some of his income came from a bequest from his father of 724 acres in Co. Clare and £4,000 in government stock; more came from a position in the established church – he was vicar-general of the diocese of Tuam – in which he succeeded his father (1845) and for which he was paid an annuity of £106 in compensation after disestablishment (1871). He was able to purchase lands at Clonbulloge and seems to have inherited property at Castlejordan, Co. Meath, through his wife, Maria Arabella (whom he married in 1849 and who died in 1885), daughter of Capt. John Armit of Dublin and granddaughter of Sir Duke Gifford of Castlejordan. He was a JP in Co. Kildare as well as King's Co.
From childhood and throughout life Joly was a bibliophile. He formed a collection of books, manuscripts, prints, maps and sheet music which in 1863 he formally donated to the RDS (of which he was a member) with the proviso that whenever a library for public use should be established in Dublin by act of parliament the collection be transferred to it. In the Dublin Science and Art Museum Act (1877) the ‘Joly Library’ was designated with the Royal Dublin Society's own collection as the nucleus of a new National Library of Ireland (opened on 29 August 1890). Joly never ceased collecting. After his death the books forming part of his estate were sold by auction in over 2,000 lots. The Joly collection in the NLI contains 23,000 printed volumes, many unbound papers and prints as well as Irish and Scottish song music. It is notable for books relating to the history and topography of Ireland and to revolutionary and Napoleonic France – Joly and his brothers had in 1846 visited Charneux (incorporated into France, 1795–1814) to learn more about their forebears. Jaspar Joly died 25 December 1892 at 38 Rathmines Rd, his Dublin home for over 35 years, and was buried at Clonsast; he left three daughters. There is a portrait of Joly by Stephen Catterson Smith (qv) (1806–72) in the RDS.