An anonymous historical compilation in two parts, each preceded by a preface, and copiously annotated. Book I (fos 1-56) comprises 47 chapters, consisting of annals of the history of Ireland to the time of Conn Cedchathach, said by the author to be taken mainly from the works of Keating, O'Flaherty and Warner, and serving as the introduction to Book II. Book II consists of translations from Irish of (1) the narrative of the battle of Maighe Lena (fos 58-92), from a manuscript of the 'short recension': see the critical edition by K. Jackson, Cath Maighe Lema (Dublin, 1938); (2) an account of the battle of 'Macroon' (Maighe Mucrima) (fos 94-119): this is not taken from the text printed by W. Stokes, Revue Celtique, Vol. 13 (1892), but its opening resembles that of the version in modern Irish, 'Cath Maighe Mucraimhe', mentioned there on pp. 428-429. On fos 119v-161v are further annals to AD 1175 from the same sources, followed (fos 162-191v) by genealogies of Irish families, a list of kings of Ireland and miscellaneous historical notes.