O'Mahony, Eoin Seosamh (‘Pope ’) (1904–70), barrister, genealogist, journalist, and broadcaster, was born in Monkstown in Cork on 22 March 1904, the only surviving son of Daniel O'Mahony, city analyst for Cork, and his wife (and cousin), Julia O'Keeffe. He was at school in Cork at a kindergarten run by the Misses Kelly on South Mall and at Christian Brothers’ College before boarding at Clongowes, where he was an intermediate prizeman. It was there, by his own account, that he acquired the nickname ‘Pope’ because, with an innocence that was to become characteristic of the man, he proclaimed that to be pope was his ambition in life. As a boy of eleven he suffered from bronchial illness and became a patient of Dr George Sigerson (qv), who advised him to read Mrs Morgan O'Connell's Last colonel of the Irish brigade. This kindled his lifelong interest in history.
O'Mahony finished his schooling at Presentation Brothers’ College, Cork, from which he won an exhibition to UCC to study medicine – becoming, as he liked to remark, the third generation of failed medical students in his family. He was more successful as a debater and became gold medallist and auditor of the university philosophical society. His debating successes continued when he moved to Dublin to read for the bar. He was auditor and gold medallist both of the law students’ debating society at King's Inns and of the College Historical Society of TCD. In 1930, as auditor of the College Historical Society, he created controversy when at the dinner after his inaugural meeting he toasted Ireland rather than the king and found himself impeached. At Trinity he was also co-founder with Terence de Vere White (qv) of a student journal called College Pen and held office in Trinity's Cumann Gaelach, to which he once invited Éamon de Valera (qv) as a guest.
O'Mahony was called to the bar in 1930 and was a pupil of John Lymbrick Esmonde (qv), a former MP for the Irish parliamentary party and subsequently a member of the dáil and fourteenth baronet of the name. But O'Mahony's own political allegiance was on the republican side, with Fianna Fáil, whom he represented from the mid-1930s on Cork borough council and Cork county council. He also came within 500 votes of being elected to the dáil for South-East Cork in the 1938 general election. Appointed state counsel for Cork, he sometimes disconcerted the court by pleading for leniency for those he was retained to prosecute.
O'Mahony found the restraints of regular legal practice and routine party politics too restrictive and preferred to concentrate on causes that engaged his own enthusiasm. He was standing counsel to the shareholders in the Great Southern Railway before its nationalisation in 1944. After the war he took up the cause of refugee children, for which he was later decorated by the Federal Republic of Germany. He spent over a year in London, where he had been called to the bar at the Inner Temple, seeking the release of IRA prisoners, and he appeared for Brendan Behan (qv) when the latter was sent to prison in Manchester in 1947 and again in Dublin in the following year. At the British general election of 1950 he was election agent for an anti-partitionist candidate running in the Gorbals district of Glasgow.
Meanwhile, O'Mahony's personal life became steadily more disorganised. Debts he had incurred through generous hospitality to friends and donations to good causes forced him to sell his family home in Douglas. Hopes he may have entertained of marriage were dashed when he was turned down, quite properly in his own phrase, by three different young ladies, one of whom was the niece of the then O'Conor Don. His practice at the bar disappeared when he broke with Fianna Fáil in 1945 on their treatment of IRA prisoners. He applied unsuccessfully on several occasions to be appointed a district justice. He then drifted into a peripatetic lifestyle as a kind of errant scholar. He traced the steps of the Wild Geese on visits to continental Europe, while at home he was seen regularly hitching lifts on the public highway. He invited himself to stay with friends, many of whom were pleased to have him for a period – especially if they had been recipients of his bountiful hospitality before his funds ran out. But he continued to be improvident with whatever money came his way, never able to resist the generous gesture. Dublin became his base, and he was a habitué of the graduates’ rooms in Trinity College. The white beard he grew made him seem venerable by the time he was fifty.
O'Mahony devoted himself to family history, and sought unsuccessfully to be employed in the new Genealogical Office; he had been one of the founders of the Irish Genealogical Research Society. He had a particular interest in the surviving native nobility and also in commemorating members of the ascendancy who had ‘espoused Ireland’. When Hubert Butler (qv) found himself embattled because of his opposition to Archbishop Stepinac of Croatia, O'Mahony went to stay with him and, with characteristic loyalty, put a notice in the newspapers announcing the fact. The integration into Irish life of the surviving members of the gentry, on whose pedigrees he was well versed and at many of whose houses he was a regular guest, became a mission. The flavour of his talk, pouring forth torrents of information in a mellifluous Cork accent, entertaining and sometimes insightful but at other times long-winded, wanting in accuracy, and slightly absurd, is captured in an essay published by the writer John Ryan (qv) entitled The lost umbilical chord and in a less kind depiction in Terence de Vere White's autobiographical work A fretful midge.
O'Mahony was a constant speaker at debates of student societies and local historical societies. His letters, book reviews and obituaries were often to be found in the columns of the newspapers, and were generally well worth reading. The weekly column he wrote in the Sunday Review (1959–62) was less inspired. He had not the discipline for regular or extended writing. He resigned when the paper published a report that he had supplied on a confidential basis from the US breaking the news that President Kennedy would visit Ireland in the following year.
O'Mahony was able to indulge his passion for family history when, between 1962 and 1967, Radio Éireann retained him to compere a programme broadcast at Sunday lunchtime called Meet the clans, in which people of a name were gathered together to hear his account of the family history and interviews with eminent or aristocratic persons of the name. There were several highly successful visits to the US for the programme. This led, in time, to two terms as a visiting professor at the University of South Illinois, where his brief was to record on tape his memories of Irish life and other lore that had come his way.
Commemoration became a special interest. Although O'Mahony had been a republican, he became convinced that less than justice had been done to the contribution made by constitutional nationalists. He was active in the campaign to save Derrynane, the home of Daniel O'Connell (qv). It was his inspired idea that de Valera should be asked to attend in his capacity as chancellor of the NUI at the celebration in Wexford in 1956 of the centenary of the birth of John Redmond (qv). In 1967 he was the sole Irish presence at the commemoration at Messines of the fiftieth anniversary of the death in action of Redmond's brother William (qv). He was often seen bearing wreaths he could probably ill-afford to the graves of other less prominent figures whom he thought should not be forgotten. O'Mahony played an active part in the Irish Georgian Society from its foundation, and opposed the destruction by the ESB of the Georgian buildings in Fitzwilliam Street, Dublin. He was one of a number of colourful figures who flourished under the patronage of Mariga Guinness (qv), a German princess who had founded the society with her husband, Desmond.
O'Mahony continued to nurture political ambitions, however futile. In the 1957 general election he ran as an independent in Wexford but polled only 759 votes. He was an unsuccessful candidate on several occasions for both university constituencies in Seanad Éireann. In 1966 he made what was the first ever bid to take advantage of the provision in the constitution giving four local authorities a right to nominate a candidate for the presidency. But control of corporations and county councils by the political parties prevented him from receiving a single nomination. The following year he received just over 800 votes when he contested a by-election in Cork for Clan na Saoirse in which, despite his love of continental Europe and interest in the many Irish connections to be found there, he opposed Irish accession to the EEC. He feared that all native industries would be swallowed up by multinationals.
O'Mahony's health had begun to deteriorate before he collapsed and died suddenly on 15 February 1970 at his nephew's house in Monkstown, Co. Dublin. He had been attending a retreat organised by the Order of Malta, of which he (like his father before him) was a longstanding Knight of Magistral Grace. Among many generous tributes was one in The Times stating that if he had had a Boswell he was the stuff of Johnson. He was buried in the family grave in St Joseph's cemetery in Cork given to his grandmother by Fr Theobald Mathew (qv). He was survived by two sisters, one of whom, Sheelah, had had a son by the sixteenth Lord Gormanston, a fact he never mentioned despite his affection for the nephew, his regard for the nobility, and interest in bars sinister. Au fond, he was a devout and conservative catholic.
Some discounted O'Mahony as a serious figure, but he inspired much affection. A group of his friends led by Mrs Guinness and Nora O'Sullivan, who had assisted him on the Meet the clans programme, sought subscriptions for a bursary to commemorate him to be awarded to scholars studying the history of the Irish abroad. Although not widely publicised, it attracted some 500 subscriptions and is administered by the RIA. For many years around the time of his anniversary, friends assembled for a commemorative dinner following a mass for the repose of his soul. A portrait of him by David Hone hangs in the NGI and a bust by Seamus Murphy (qv) is in the RIA. There are also portraits by Harry Kernoff (qv) and Eithne McNally.