This chronicle, first published in 1866, is a transcription and translation of a manuscript that gives an account of the earliest-known period of Ireland's history until 1135, describing the leaders and tribes of the Scoti, as the Romans called the inhabitants of the island. Forming part of the Rolls Series of publications of manuscripts concerning the history of Great Britain and Ireland during the Middle Ages, this work was edited and translated by William Hennessy (c.1829–89), a linguist who was interested in the preservation of the Irish language. His extensive introduction to the text examines the complicated history of the manuscript's previous versions, and his essay has been considered a valuable source for historians. The text has transcriptions of the manuscript in its original Irish and provides corresponding English translations, as well as a glossary.