Dubhaltach MacFhirbhisigh (fl.1643-January 1671) was born in the parish of Lackan, in the Barony of Tireagh, Co. Sligo, sometime in the first half of the 17th centaury. He was the last of the "ollav seanchus" or professional historians of a family that had practised the art for at least five hundred years, the greater part of it in Ui Fiachrach.

Little is know for certain of his early life, and the manner of his death is shrouded in mystery. Even the years of his known activities leave many questions both unanswered and unanswerable.

His greatest achievement was compileing and writing An Leabhar Genealach, or The Book of Irish Genealogies, written mainly in the town of Galway in the years 1649/1650, though with important additions right up to the time of his death. It is probably the largest single collection of Irish genealogies, and certainly among the most important. It was finally published in Ireland in the summer of 2004. It was edited by Nollaig O'Muralie, who had begun work on the book in 1971.

Dubhaltach is believed to have been murdered at a sheebeen in Co. Sligo in January 1671 by a certain Thomas Crofton, though the circumstances are unclear. The names of his brothers are recorded, but it is not know if Dubhaltach was ever married or if he had children. The name MacFhirbhisigh is now extinct and replaced its anglacised form, Forbes, which is an unrelated Scottish surname of Norman origin. Bearers of the name descended from the Clan MacFhirbhisigh are mainly found in countys Mayo and Roscommon in Ireland.

Sources

• "The Celebrated Antiquary", Nollaig O Muraile, Maynooth, 1996.
• "Leabhar Mor nGenealach", published 2004; Nollaig O Muralie, editor.