Leabhar na nGenealach

Leabhar na nGenealach ("Book of Genealogies") is a massive genealogical collection written mainly in the years 1649 to 1650, at the college-house of St. Nicholas' Collegiate Church, Galway, by Dubhaltach MacFhirbhisigh. He continued to add material until at least 1666, five years before he was murdered in 1671. The original 17th century manuscript was bequeathed to University College Dublin (UCD), by Dublin solicitor Arthur Cox in 1929, and can be consulted in UCD Library Special Collections. The manuscript can be viewed online at Irish Script on Screen, which is available in English, and in Irish Archived 6 March 2021 at the Wayback Machine. Leabhar na nGenealach, was reprinted, and published in a five volume edition in Dublin in 2004 as The Great Book of Irish Genealogies.

The book contains notes on families from all parts of Ireland, from Gaelic Scotland, as well as the pre-Gaelic, Viking and Old English peoples of Ireland. It consists of eight hundred and seventy one pages, 95% of which is in Mac Fhirbhisigh's handwriting. The remainder is in the hand of an unknown amanuensis, and incorporates some pages written in 1636 by Mícheál Ó Cléirigh. While MacFhirbhisigh worked on commission from the Poor Clares in Galway and may have earned income as a tutor, he appears to have had neither patron nor sponsorship of any sort while working on this book. It was seemingly a labour of love for the writer.