Dictionary of National Biography, 1885-1900/O'Callaghan, John Cornelius
O'CALLAGHAN, JOHN CORNELIUS (1805–1883), Irish historical writer, son of John O'Callaghan, who was one of the first catholics admitted to the profession of attorney in Ireland after the partial relaxation of the penal laws in 1793, was born at Dublin in 1805. He was educated at the jesuit school of Clongoweswood, co. Kildare, and afterwards at a private school at Blanchardstown, near Dublin, and was called to the Irish bar in 1829, but, preferring a literary life, did not practise. He contributed to a weekly newspaper, published in Dublin from 1830 to 1833, called ‘The Comet,’ which advocated the disestablishment of the protestant church in Ireland, and which counted O'Connell among its contributors. When the ‘Comet’ ceased he wrote for the ‘Irish Monthly Magazine,’ and his contributions to these two journals were collected, and were, with other writings of his, published under the title of ‘The Green Book; or Gleanings from the Writing Desk of a Literary Agitator’ (Dublin, 1840, 8vo). When the well-known ‘Nation’ newspaper was started in 1842 as the organ of the party afterwards known as the Young Ireland party, O'Callaghan joined the staff, and its first number contained ‘The Exterminator's Song,’ written by him, and subsequently republished in the ‘[Spirit of the Nation]],’ a collection of the poetry of the ‘Young Irelanders.’
It is, however, as an historical writer that O'Callaghan has acquired fame. His first principal work of the kind was his edition of the ‘Macariæ Excidium; or the Destruction of Cyprus,’ the secret history of the revolution in Ireland from 1688 to 1691, written by Colonel Charles O'Kelly [q. v.], an officer of James II's army. On this work, which was published in 1846 (Dublin, 4to), O'Callaghan spent four or five years, and his notes to it are most valuable. About twenty-three years after this he published his greatest work, his ‘History of the Irish Brigades in the Service of France, from the Revolution in Great Britain and Ireland under James II to the Revolution in France under Louis XVI’ (Glasgow, 1869, 8vo), on which he spent ‘more than twenty-five years' research and labour,’ but for which he could not find a publisher in Dublin. Though very diffuse in style, and in some respects unscholarly (both index and references being very incomplete), this history displays the most careful research, and must always be considered a standard work. The ground that it breaks is, moreover, practically new, the previous work by Matthew O'Connor [q. v.] being little more than an essay which was left unfinished owing to O'Connor's death.
Though by nature a student, O'Callaghan took a keen interest in politics, and was a strong admirer and supporter of O'Connell; it was he, with John Hogan [q. v.], the sculptor, who placed a crown on O'Connell's head at one of the well-known ‘monster’ meetings of O'Connell's supporters held at the Hill of Tara, the ancient crowning-place of the kings of Ireland.
O'Callaghan died in Dublin on 24 April 1883, in his seventy-seventh year.
Sir Charles Gavan Duffy, in his ‘Young Ireland,’ describes him as a tall and strong man, ‘speaking a dialect compounded apparently in equal parts of Johnson and Cobbett, in a voice too loud for social intercourse. “I love,” he would say, “not the entremets of literature, but the strong meat and drink of sedition;” or “I make a daily meal on the smoked carcass of Irish history.”’
[Freeman's Journal, 25 April 1883; Irish Monthly, vol. xvii.; Duffy's Young Ireland; Lecture by Dr. More Madden on O'Callaghan, given in Dublin in February 1892; Freeman's Journal, 5 Feb. 1892.]