Eustace, John Chetwode (1762/3–1815), catholic priest and writer, was born in Co. Kildare. Both his parents were reputed to belong to gentry families, his father's in that county. It seems likely that through his father, whose name is not known, he was descended from Benjamin Chetwood (d. 1728) of Woodbrook, Queen's Co., who married (1703) Anne Eustace (d. 1714), daughter and co-heiress of Sir Maurice Eustace (d. 1703) of Harristown, Co. Kildare, which he inherited and briefly represented in parliament (1713–15). Chetwood's elder son, Eustace, assumed the name Chetwood Eustace and married Susanna Crossly, daughter of Aaron Crossly, author of the Peerage of Ireland (1723). It seems likely that Chetwood Eustace had a son who became a catholic, or married one, and was the father of the priest.
John Chetwode Eustace studied in England at Sedgley Park near Wolverhampton, Staffordshire, and (from 1774) in France at St Gregory's College, Douai. Although he was attracted to the English Benedictines who ran the college, he was ordained priest for the diocese of Kildare. His early career was in England, where he was said to have been a tutor – presumably to a catholic family – and where he was friendly with Edmund Burke (qv). He is supposed to have told Burke: ‘I was born in Ireland but I left it early in life. My family and connections are English’ (Gillow). On the founding of the Irish national seminary at Maynooth he was appointed professor of rhetoric (27 June 1795) but it seems likely that he had very few students. After about two years’ residence in Ireland he resigned (25 November 1797) and returned to England and to tutoring.
Eustace led a life unusual for a secular priest of Irish birth and family. He never served in a parish but moved in the circles of the English gentry, protestant as well as catholic. In 1796 he wrote a poem in honour of Earl Camden (qv) and gave a copy to Burke. In 1802, with three companions, he toured Italy, studying antiquities. In 1805 he accompanied George Petre, the eldest son of the catholic nobleman Lord Petre, to Jesus College, Cambridge, acting as his tutor (or perhaps his chaplain). There he was befriended by the senior tutor, the geologist Edward Daniel Clarke, who had travelled very widely (he was in Siberia in 1800) and who encouraged Eustace to publish his manuscript account of his visit to Italy. This appeared as A tour through Italy (1813), was favourably reviewed, and under the new title A classical tour through Italy went into many editions. Eustace incurred the displeasure of the local catholic bishop, John Milner (vicar apostolic of the midland district, 1803–26), a champion of theological orthodoxy, who considered his views, conduct, and associations to be indulgent and improper. In 1815 Eustace embarked on another tour of Italy but on 1 August 1815, aged fifty-two, he died at Naples of malaria. His obituary in the Gentleman's Magazine (which had reviewed his Tour extensively) was fulsome; but Milner, writing afterwards in a catholic journal, was scathing, accusing him of ‘gadding with Protestants’ and ‘heresy’ (Husenbeth).
A versatile and talented writer, Eustace was the author of An elegy to the memory of the Right Honourable Edmund Burke (1798), A political catechism (1810), An answer to the charge delivered by the bishop of Lincoln (1813; repr. 1819), A letter from Paris to George Petre (1814), and The proofs of Christianity (1814). His writings were remarkably free of acrimony. Eustace left one brother, said to be the last surviving Eustace of his line.