Collectively the Irish annals represent a substantial and important source for the history and culture of Ireland. These texts provide the primary witness for much of early medieval Irish history, and for many key events and persons up until c.1600. Many of the most important of these texts passed into the possession of 17th-century Anglo-Irish scholars, and it was principally their work which formed the basis for all modern scholarship on them. However, examination of their work shows that a number of the accepted hypotheses rest upon assertions of opinion, and are unsupported by any textual evidence. This book first re-examines the manuscript evidence, commencing with an account of the primary manuscript witnesses for the ten most characteristic annalistic texts. It then reviews the scholarly literature relating to the annalistic corpus and identifies those hypotheses that are not supported by the available evidence. Next, based upon a critical evaluation of both the textual and chronological characteristics of the texts, the book establishes, where possible, the place, author(s), time and salient characteristics of the compilations that have contributed to the development of these ten texts. The penultimate chapter reviews the chronology of these texts and identifies the basis for a synchronised chronology for them all.