Terence Francis MacCarthy
Terence Francis MacCarthy (born 21 January 1957), formerly self-styled Tadhg V, The MacCarthy Mór, Prince of Desmond and Lord of Kerslawny, is a genealogist, historian, and writer. Born in Belfast, Northern Ireland, he is a resident of Morocco. His last name is sometimes published as McCarthy.
On 28 January 1992, the Irish Genealogical Office conferred courtesy Chief of the Name recognition to Terence MacCarthy as the MacCarthy Mór, the title of the chief of the MacCarthy sept or clan. The title literally means "the great MacCarthy." The MacCarthys had been princes of Desmond, and earlier, through the Eoghanacht of Cashel, the kings of Munster. Terence MacCarthy claimed the title based on tanistry rather than primogeniture, and stated that his father renounced the title in his favour in 1980. He then led a very successful affiliation of MacCarthy clan associations in Ireland, Canada, and the United States. These associations throve, because of good organisation and the strong appeal of heritage tourism at the time. MacCarthy instituted a quasi-chivalric order, the Niadh Nask, and conferred titles of nobility on his supporters.
In the early-1990s, MacCarthy joined the International Commission on Orders of Chivalry (ICOC), an organisation whose stated purpose is to examine Orders of chivalry to determine their legitimacy. By 1996, he was serving as Vice-President under the ICOC's founder and President, Robert Gayre. Gayre and MacCarthy used the ICOC's influence to promote the claimed legitimacy of the Niadh Nask, and MacCarthy's fraudulent nobiliary claims. At the same time, Gayre served as MacCarthy's "Constable" in the Niadh Nask. The other eight members of the Board of the ICOC in 1996 included Patrick O'Kelly, who claimed to be "Baron O'Kelly de Conejera", and six others who were members of the Niadh Nask. The ICOC's own Register listed its Vice-President matter-of-factly as "The MacCarthy Mór, Prince of Desmond".  In 1996, Robert Gayre died and Terence MacCarthy assumed his position as President of the ICOC. For the next three years, he continued to use its offices, influence and publications to lend credence to his nobiliary claims. 
On 20 June 1999, The Sunday Times in Dublin published an article questioning both the facts of MacCarthy's particular application of tanistry, and the verity of his descent from former chiefs of the MacCarthy clan. Various public statements on both sides were released over the next few months. MacCarthy's critics alleged that he was an impostor who misused his genealogical skills to fraudulently claim the title, then exploited it for personal financial gain and aggrandisement. His supporters countered that he was an excellent organiser who delivered on every promise made to clan associations. They argued that a culturally inappropriate and impossibly stringent standard was applied to MacCarthy's pedigree. They also claimed that MacCarthy was being singled out because of jealousy of his success, and possibly due to his political and religious views.[clarification needed] Investigation of the case was rendered more difficult due to the refusal of the Genealogical Office to release all documents relating to the 1992 courtesy recognition. The Irish Freedom of Information Act of 1997 does not apply retrospectively, but documents relating to the case from April 1998 onwards were released. Sean J. Murphy, a County Wicklow genealogist, has published online accounts of the MacCarthy Mór case and also a full-length book. It is now clear that Terence MacCarthy's claim to be the MacCarthy Mór was based on fabricated documentation, and rather than being aristocrats of Munster origin, his ancestors were ordinary Belfast working people.  The surname of MacCarthy's paternal grandfather, Thomas, is listed on his birth certificate as "MacCartney", rather than the expected "MacCarthy". 
On a practical level, the issue was settled by two events. In August 1999, the Irish Genealogical Office nullified its previous recognition of Terence MacCarthy as the MacCarthy Mór. On 9 October 1999, after losing the support of the Niadh Nask, Terence MacCarthy abdicated the title, which his younger brother, Conor, then claimed. Barry Trant MacCarthy, a resident of England, applied for recognition the title, but the Genealogical Office never made a decision on the matter. In 2003 the government discontinued the practice of granting courtesy recognition to Chiefs of the Name.
- Sliocht Cormaic of Dunguile, sept of the MacCarthy dynasty into whose pedigree Terence MacCarthy inserted himself
- James Shortt, accomplice of MacCarthy
- McCarthy, Pete (2004) The Road to McCarthy: Around the World in Search of Ireland. London; New York: Fourth Estate. ISBN 0-00-716212-X.
- Murphy, Sean J (2004) Twilight of the Chiefs: The Mac Carthy Mór Hoax. Bethesda, Maryland: Academica Press. ISBN 1-930901-43-7.
- pp. 300–303,"The Sword and the Green Cross: The Saga of the Knights of Saint Lazarus from the Crusades to the 21st Century" by Max J. Ellul, Authorhouse, 2011, ISBN 145671421X
- Sean J. Murphy, "Twilight of the Chiefs: The MacCarthy Mór Hoax", Academica Press, 2001, ISBN 1930901437