He also studied (about A.D.

1595) at Burren, in the county Clare, in the literary and legal school of the O'Davorens.

His pedigrees of the ancient Irish and the Anglo-Norman families, was compiled at the College of St.Nicholas, in Galway, in the year 1650.

It may interest some of our readers to peruse the title of this work, although its length would certainly horrify a modern publisher:-- "The Branches of Relationship and the Genealogical Ramifications of every Colony that took possession of Erinn, traced from this time up to Adam (excepting only those of the Fomorians, Lochlanns, and Saxon-Gaels, of whom we, however, treat, as they have settled in our country); together with a Sanctilogium, and a Catalogue of the Monarchs of Erinn; and, finally, an Index, which comprises, in alphabetical order, the surnames and the remarkable places mentioned in this work, which was compiled by _Dubhaltach Mac Firbhisigh_ of Lecain, 1650." He also gives, as was then usual, the "place, time, author, and cause of writing the work." The "cause" was "to increase the glory of God, and for the information of the people in general;" a beautiful and most true epitome of the motives which inspired the penmen of Erinn from the first introduction of Christianity, and produced the "countless host" of her noble historiographers.
Mac Firbis was murdered[19] in the year 1670, at an advanced age; and thus departed the last and not the least distinguished of our long line of poet-historians.

Mac Firbis was a voluminous writer.