These dates are entirely at variance with the chronology of the Annals. We are entitled to criticise them on the assumption that the dates of the Annals for the battles of Segais, Sligech, and Cuil Conaire are approximately correct. O’Duinn’s figures would place Segais _c._ 475 instead of 502 (or 500), Sligech _c._ 512 instead of 543 (or 547), Cuil Conaire _c._ 517 instead of 550. But if we omit from his list Eogan II. and Duach II., and then reckon back from 577, we get approximately dates assigned in the Annals to the second and third of these three battles, namely, 551 for Cuil Conaire, 546 for Sligech; while the contradiction between the duration of Eogan Bel’s reign and the date of Segais is the same here as in the other sources. If Segais was fought in 502 and Sligech in 546/7, and Eogan Bel reigned thirty-seven years, then seven or eight years are left unaccounted for, and the reign of the second Duach serves to fill this interval. But there is no room for Eogan Srem between the battle of Segais and the death of Aed. Again, if we take Duach I.’s death at Segais in 502 as a fixed point, and reckon backward with O’Duinn’s figures, we find 482 for the accession of Duach I., 471 for the accession of Ailill Molt, and 451 for the accession of Amolngaid. If Amolngaid followed Dathi in 428, this would imply an error of about twenty-four years. We have now the clue to the construction of O’Duinn’s list. A period of _c._ 153 years from the accession of Amolngaid to the death of Aed had to be accounted for. The recorded regnal years were insufficient, and the defect was supplied by an impossible interpolation in the sixth century, whereas it was in the fifth century, in the period anterior to Duach, that the supplement was chiefly needed. Having established this point, we need not consider further the succession of kings subsequent to Duach Tenga Uma.