The Last Titular King of Leinster

'The Last Titular King of Leinster' and the Hauskirchen Succession

Revised and supplemented early August 2026.
© Michael Forrestal Keller
The study can be Read on ForrestalHistory.com at: https://forrestalhistory.com/the-kavanaghs-last-titular-king-of-leinster/

The study traces the story of Baron Henry Kavanagh, a captain in the Imperial Austrian service, whose attempt in 1813 to document his patrilineal descent from the Kavanagh family of Inch, Co. Carlow, in order to succeed to the Hauskirchen estate in Lower Austria, set in motion an investigation by the Office of Arms in Dublin. Drawing on a set of previously unpublished field agent letters, discovered by the present author on 5 May 2026, as well as on Austrian diplomatic correspondence, Irish memorial deeds, wills, draft pedigrees, parish registers, and ledger stones, the study reconstructs the pedigree of the Kavanagh families of Inch and Rocksavage, Co. Carlow, and their relationship within the Kavanagh dynasty of Leinster. The author has determined that these letters were used to construct a portion of the registered pedigree of the Kavanagh dynasty contained in the National Library of Ireland, GO MS 171, a manuscript later drawn upon as a source by other publications (though the letters themselves do not seem to have been previously known to the authors of the later publications as an underlying source).

Among the most remarkable discoveries in the letters is a firsthand account, recorded by a field agent, identifying Murtagh Kavanagh of the Palace of Marley, Co. Carlow, as ‘The Last Titular King of Leinster,’ and reporting that upon his death in 1746 he transferred the Kavanagh charter horn, the crown of Leinster, the royal sceptre, and the royal insignia (perhaps the Liath Meiscith), to Simon Kavanagh of Rocksavage, who later conveyed the items to Thomas Kavanagh Sr. of Borris (1728–1790). The study also recovers the story of the pedigree of the Kavanaghs of Inch and Rocksavage, how it was preserved, by whom, and under what circumstances it was disclosed, revealing a tightly bound kinship network of Catholic gentry and middlemen families in Co. Carlow and Wexford that endured across generations of displacement and dispossession.