Orpen, Goddard Henry (1852–1932), lawyer and historian, was born on 8 May 1852 in Dublin, the fourth son of the five sons and three daughters of John Herbert Orpen, barrister, of Dublin, and Ellen Susan Gertrude, youngest daughter of Rev. John Richards of Grange (latterly Monksgrange), Co. Wexford. He was educated at Tipperary grammar school and in 1869 entered TCD, where he displayed early academic aptitude, obtaining an exhibition at entrance, a scholarship in classics, and several first honours. He graduated BA in 1873 and four years later was called to the English bar at the Inner Temple, London.
On 18 August 1880 Orpen married the writer Adela Elizabeth (d. 1927), the daughter and heiress of Edward Moore Richards, engineer, of Monksgrange, Co. Wexford. They lived for the next two decades at Bedford Park, Chiswick, London, with their daughter Lilian (b. 1883) and son Edward (b. 1884). Orpen's passionate interest in historical and antiquarian research gradually supplanted his languishing legal career. He translated and edited a French rhymed chronicle about the Anglo-Norman conquest of Ireland, entitled The song of Dermot and the earl (1892), and translated Emile de Laveleye's Le socialisme contemporain (The socialism of today, 1884), to which he added a chapter on English socialism. Adela also occupied herself with writing, publishing four novels and contributing numerous articles and short stories to the London press.
In 1900 Adela inherited Monksgrange and, rather reluctantly, the Orpens left London for a more secluded life in Ireland. While Adela largely relinquished her literary career to manage and improve the estate at Monksgrange, Orpen now devoted his time fully to writing. His major work was Ireland under the Normans (vols 1–2, 1911; vols 3–4, 1920), which argued that the Norman invasion benefited the Irish, leading to advances in agriculture and trade. A lecture to the New Ross Literary Society was later published as New Ross in the thirteenth century (1911). Orpen was elected a member of the RSAI (president, 1930–32) and the RIA (1911), and contributed historical articles to their journals as well as to periodicals such as the American Historical Review (1913–14) and Cambridge Medieval History (1932, 1936). Though his literary work was recognised by an honorary doctorate from TCD (1921), he felt increasingly isolated, as Monksgrange was targeted during the civil war and raided on several occasions. Adela's health declined in the later 1920s, but she published a memoir of her childhood, Memories of the old emigrant days in Kansas, 1862–1865 (1926), before her death on 17 February 1927. Orpen's final work was The Orpen family, a personal family history printed for private circulation in 1930, which contains a portrait of the author by Seán O'Sullivan (qv). Orpen died 15 May 1932 at Monksgrange. His papers are in the NLI.