O'Murnaghan, Arthur Walter (1872–1954), polymath, artist, designer, and actor, was born in Southampton, England, eldest child among at least three sons and two daughters of Arthur O'Murnaghan (of a Loughbrickland, Co. Down, family), employed in Southampton as an official of the ordnance survey, and Rachel O'Murnaghan (maiden name unknown), who was Welsh. Educated at Southampton grammar school, he won a scholarship to Cambridge, but instead decided to take up a four-year apprenticeship to a dispensing chemist. He next found employment with the Carnegie free public library in Southampton, and qualified as a librarian. He moved to London and – although he had received no formal art education – designed floral wallpapers, some of which were sold by Liberty. He was increasingly attracted to the exploration of his Irish heritage, which in turn led to an interest in a wide range of scholarly pursuits. He joined the Gaelic League on its inception in 1893, becoming a close friend of Arthur Griffith (qv) and Douglas Hyde (qv), and designed stencilled badges for the Gaelic League's Oireachtas (1905–17). He moved to Dublin in 1898 and wrote and drew for the United Irishman from 1902. As demand for floral wallpapers declined, he found employment as a cinema piano and organ accompanist, especially at the Volta Cinema, Dublin, in 1909, and he later opened a pharmacy business in Rathgar, Dublin.
He designed (c.1917) five Sinn Féin Christmas cards, preserved in the National Museum of Ireland. O'Murnaghan taught himself calligraphy, and by 1922 he completed an illumination of ‘The vision of Brigid’. The illustration (NLI collection; reproduction in de Breffny, 234), which had taken almost three years to complete, was, he proclaimed, ‘the most beautiful and most representative design I could create for “the idea” of the name of my country’ (Gordon Bowe & Cumming, 160). In 1922 an Irish Republican Memorial Committee was established to commemorate the Easter rising; members included Maud Gonne (qv), Padraig de Brún (qv), and Ella Young (qv). They agreed that an illuminated work should be commissioned, commemorating the names of those Volunteers who had died in the rising. O'Murnaghan's work met with the approval of the theosophist, republican, and jeweller Mia Cranwill (qv), treasurer of the fund committee. In September 1923 his ornamentations appeared in the first number of the Dublin Magazine for a series by Ella Young, ‘The adventures of Gubbaun Saor and his son’.
O'Murnaghan had given up the pharmacy business when he won the Free State government commission in 1922 to execute the illumination of The book of the resurrection (Leabhar na hAiséirighe). Copies of the ‘Eire’ page were sold in an effort to raise funds for the commission. Though often interrupted, the work became O'Murnaghan's life's mission and masterpiece. He began on Easter eve 1924, and by spring 1927 had completed the first nine and a half folios, at a weekly fee of 30s. (£1.50), ‘carrying on,‘ he wrote in the dedication, ‘after more than a thousand years the Irish tradition of beautiful sacred books’ (Gordon Bowe & Cumming, 160). His techniques were similar to those of the medieval artists (he ground and mixed his own paints), and his work is based on motifs and elements characteristic of the earlier manuscripts. His work is, however, not merely a faithful copy; it reveals other artistic influences, notably those of oriental illustrations and eastern mysticism, and was very influential in the twentieth-century development of the artistic treatment of ‘Celtic’ themes. The book was not bound; the decoration of the last of twenty-six calf-vellum sheets was completed in 1951, but in 1954 O'Murnaghan was writing a key to each of the folios; the work was unfinished at his death. Four drawings for the book are in the county museum, Armagh, and the whole volume is in the NMI. In 1928 he completed a Celtic motif design for a Donegal hand-tufted carpet, installed in the dáil, in Leinster House. In 1929 his decorative borders illustrated Hilton Edwards's essay ‘The historical pageant’ in Mac Liammóir's The ford of the hurdles: a masque of Dublin, celebrating Dublin civic week. In 1932 his original designs for the cover of Saorstat Eireann, the Irish Free State official handbook edited by Bulmer Hobson (qv), were published by the Talbot Press.
O'Murnaghan had worked on set design in Daisy Cogley's Little Theatre in Harcourt St., Dublin, and in 1928 he was persuaded by Hilton Edwards (qv) and Micheál MacLiammóir (qv) to become stage manager, actor, designer, and composer with the Gate Theatre, Dublin. He acted in at least seventeen plays, and also contributed music; MacLiammóir noted that during performances of ‘The old lady says no’ by Denis Johnston (qv) in the Gate Theatre (1929) O'Murnaghan wielded the drumsticks with ‘a rapt expression like a druid at some sacred rite’, and was like ‘an elderly saint who worshipped Angus and Lú and the ancient gods of Ireland’ (All for Hecuba, 134). He was stage manager of thirteen plays, and assistant art director of seven. He also had parts in films such as Odd man out and Another share. He toured with the Gate Theatre company to Egypt in 1936. He was interested in archaeology (he wrote on the connection between Newgrange, where he had undertaken some excavations, and the pyramids) and in herbalism and theosophy; he visited Tibet to study the Buddhist monks’ way of life. In 1936 he retired from the theatre and taught calligraphy in the National College of Art, teaching a new class on ‘Oriental design in Celtic ornament’ from 1939. The class was discontinued in the early years of the Emergency (1939–45).
O'Murnaghan died in a Dublin hospital on 8 July 1954. He was buried in Mount Jerome cemetery, Dublin, and was survived by four sons and two daughters. His late wife, Madame K. Murnaghan, had been well known in Dublin musical circles. His portrait by Estella Solomons (qv) is in the NGI. A manuscript autobiographical memoir, entitled ‘Irons in the fire’, was destroyed after his death.