Denis Florence McCarthy was born in Lower O'Connell Street, Dublin, on 26 May 1817, and educated there and at St Patrick's College, Maynooth. He acquired an intimate knowledge of Spanish from a learned priest, who had spent much time in Spain, which he was later to turn to good advantage. In April, 1834, before turning seventeen, McCarthy contributed his first verses to the Dublin Satirist. He was one of a coterie of writers whose works through the Nation (not to be confused with the American paper of the same name), which had been started by Charles Gavan Duffy in 1842. Writing under the pseudonym "Desmond", most of MacCarthy's patriotic verse appeared in this organ.
In 1846 he was called to the Irish bar, but never practised. In the same year he edited The Poets and Dramatists of Ireland, which he prefaced with an essay on the early history and religion of his countrymen. About this time he also edited The Book of Irish Ballads (by various authors), with an introductory essay on ballad poetry in general. His Ballads, Poems, and Lyrics, appeared in 1850, original and translated. His attention was first directed to Pedro Calderón de la Barca by a passage in one of Percy Bysshe Shelley's essays, and from then on the interpretation of the "Spanish Shakespeare" claimed the greater part of his attention.
The first volume of his translations, containing six plays, appeared in 1853, and was followed by further installments in 1861, 1867, 1870, and 1873. His version of Daybreak in Capacabana was completed only a few months before his death.
Until 1864 he resided principally on Killiney Hill, overlooking Dublin Bay. The delicate health of some members of his family then rendered a change of climate imperative, and he paid a prolonged visit to continental Europe. On his return MacCarthy settled in London, where he published - in addition to his translations - Shelley's Early Life, which contains an account of that poet's visit to Dublin in 1812. MacCarthy had already resettled in his native land of Ireland for some months, when he died on Good Friday, 1882 at Blackrock, Dublin. His poetical gifts were inherited by his daughter, who became a nun, and wrote as Sister Mary Stanislaus.
His poems are distinguished by a sense of harmony and sympathy with natural beauty. Such poems as "The Bridal of the Year," "Summer Longings" (alias "Waiting for the May"), and his long narrative poem, "The Voyage of St. Brendan," are among his most enduring works. The last-mentioned, which paraphrases the "Ave Maria Stella" as the evening song of the sailors, is also marked by the earnest religious feeling which marked its author throughout life. But it is by his version of Calderon that he is considered to have won a permanent place in English letters. His success is sufficiently testified by George Ticknor, who declared in his History of Spanish Literature that MacCarthy "has succeeded in giving a faithful idea of what is grandest and most effective in [Calderon's] genius... to a degree which I had previously thought impossible. Nothing, I think, in the English language will give us so true an impression of what is most characteristic of the Spanish drama, and of Spanish poetry generally." ..