"Historia Brittonum". Translated by W. Gunn. Edited by Dr. J.A. Giles. Describes the events of the history of England starting from Adam to 642 A.D. Nennius is traditionally stated as having lived in the early 9th century.
From editor's preface to the present edition:
"THE History of the Britons, which occupies the fourth place in this volume is generally ascribed to Nennius, but so little is known about the author, that we have hardly any information handed down to us respecting him except this mention of his name… The present translation is substantially that of the Rev. W. Gunn, published with the Latin original in 1819, under the following title: "The' Historia Britonum,' commonly attributed to Nennius; from a manuscript lately discovered in the library of the Vatican Palace at Rome: edited in the tenth century, by Mark the Hermit ; with an English version, facsimile of the original, notes and illustrations." The kindness of that gentleman has enabled the present editor to reprint the whole, with only a few corrections of slight errata, which inadvertency alone had occasioned, together with the two prologues and several pages of genealogies, which did not occur in the MS used by that gentleman."