Genealogy of House of O’Reilly

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While on a trip to his homeland in 2008, Nikolaus Grüger, a renowned orchestral musician and book collector, discovered an Irish Eighteenth Century manuscript in an auction in Munich.
Though from Germany, he had made his home in Ballycastle, Co. Antrim where he lived with his Irish wife, soprano Angela Feeney until ill heath forced him to return to Germany. An affordable publication of this manuscript is the fulfilment of his most cherished dream.
How the manuscript arrived in Munich is not known as the auctioneer had been sworn to secrecy about its provenance. However, we know it was compiled by Chevalier Thomas O’Gorman, an Irish exile, prominent in the Royal French Court, and an avid collector of Irish manuscripts and Annals. It was commissioned by the Count Alexander O’Reilly, then a high official and diplomat in the service of the Spanish Crown, on the occasion of his eldest son’s marriage to the aristocratic Countess Buenavista as proof of his family’s nobility. It appears three copies were deposited in archives in Spain and Ireland and three copies were retained by the count and his family; apparently it was one of these which turned up mysteriously at the auction in Munich.

Thomas O’Gorman took a scholarly approach to his work, avoiding outlandish claims and relying on an extensive range of the annals and sources available to him at the time. Using these, he traced the origins of the House of O’Reilly to several centuries before the coming of Christianity, outlining how Heber, Herimon and Ir came to Ireland from Spain and took possession of the country, ruling as monarchs and provincial kings of Ireland until Norman times and beyond. The House of O’Reilly, it is claimed, descends in a direct line from Herimon through the O’Connors, Kings of Connacht and High Kings of Ireland. O’Gorman outlines how the legitimacy of this descent is validated in a detailed disscussion of the Laws of Tanistry. There is also an interesting discussion of the emergence of Irish surnames from the period of Brian Boruma, with the application of the patronymic name of Ua or Ò to the descendents of the ‘valiant Chief Raghallagh’.
From this period and up to the Ulster plantation, the O’Reillys ruled Breifne, through internecine warfare with their neighbours and struggles with the English Crown. In hard times they found sanctury in the woods, lakes and bogs of Breifne. In the good times they were shrewd managers of finances. The fourteenth and fifteenth centuries saw them coining their own money in defiance of the authorites in Dublin. They finally surrended East Breifny to Queen Elizabeth in 1609 and their position was further undermined through the Ulster Plantation.
To this day O’Reillys and Reillys abound throughout Breifne. Countless numbers also inhabit the entire English speaking world, eminent in all areas of modern life. This manuscript is a reminder of who they once were.

About the Author

Chevalier Thomas O'Gorman was native Irish speaker, born in 1732 in Clare into a prominent Catholic family. He went into exile, being barred from advancement in Ireland by the Penal Laws to study medicine in Paris and entered military service in France, earning the title Chevalier.

 He caught the eye of Marguerite Françoise-Victoire d'Éon de Beaumont of Burgundy and they apparently eloped. This is supposed to have so outraged the young woman’s father that, in order to thwart O’Gorman’s possible inheritance of the family estates, he claimed his androgynous younger 'daughter', Charles-Geneviève, was a man, and therefore his heir, and sent him off on a military career.

This was the start of O'Gorman's relationship with Chevalier Charles-Geneviève d'Eon, now an icon of the LGBT community. He was an important spy and diplomat in the French court where his transgender identity played an important part in international intrigues. However, it also led him into political trouble and he was made to renounce his identify as a male by King Louis. As a woman, his career was over. He returned home to Burgundy to join his brother-in-law, O'Gorman who ran the successful d'Éon wine business.

O’Gorman frequently visited his wealthy clients in Ireland where he gathered important Irish historic documents and gained a reputation as a professional genealogist. Thus when Count O'Reilly approached him to compile the O'Reilly genealogy, O’Gorman was well qualified. He had played a significant role in the foundation of the Royal Irish Academy and was of central importance it its acquisition of The Annals of Ballimote and the Book of Lecan. However, the upheavals of the French Revolution meant connections with the aristocracy became perilous and O'Gorman returned to Ireland where he died in poverty in County Clare in 1809.