But Gildas conceived that the “legion” when it had done its work did not remain in the island, but returned triumphantly to Rome; and then the old foes began their ravages anew (c. 16). Again an embassy repairs to Rome and begs aid; aid is again given, and the invaders are punished. The soldiers, having given good advice to the timid natives and erected new fortifications, valedicunt tamquam ultra non reversuri. Then follows the third devastation, and the famous futile message of the “groans of the Britons” is sent to Aetius.

Now this narrative does not correspond to the course of events as we gather it from the scanty contemporary sources, but we can see how it is based on actual occurrences. The third devastation, from A.D. 407, when the army finally departed, to A.D. 446 (the third consulship of Aetius), must represent truly enough the situation of Britain in those years. The circumstance that one legion was withdrawn in A.D. 402, and that the rest departed five years later, in A.D. 407, may have been the historical motive for distinguishing a second period of devastation, which would have to fall before A.D. 407.

But a further fact may underlie this tradition of a second devastation. There is no reason to reject the statement in the Irish Annals that King Niall was slain by the Ictian Sea (Sea of Wight), that is, the English Channel, while he was invading Britain, nor is there any reason to question the date assigned to his death, A.D. 405. And if the date is right, even within a year or so, then his last incursion into Britain may be regarded as the historical foundation of the “second devastation” of Gildas.

For the legend of the Slaying of Niall of the Nine Hostages (orcuin Néill nóigíallaig) see the version edited by Professor Kuno Meyer (in Otia Merseiana, ii. 84 sqq.).

The High Kings of Ireland who may have been concerned in the “Scotic” invasions of Britain from the middle of the fourth century to the year A.D. 427 were as follows, according to the Irish tradition:—

3. The Dates of Patrick’s Birth and Captivity

The chronological framework of Patrick’s life is determined by two certain dates: the year of his coming to Ireland, which rests upon clear and unvarying tradition, A.D. 432, and the year of his death, A.D. 461. This last date is supplied by the earliest source we have (excepting Patrick’s own writings), Tírechán (302₂₉), and it is supported by the independent evidence of the Annals. For although the false, vulgar date (A.D. 493) established itself in the Annals, the true date remained inconsistently side by side with it. I must refer the reader to my discussion of the passage of Tírechán in the English Historical Review, xvii. p. 239 sqq. (1902), where I have shown that the date there given, A.D. 461, is supported by the Annals of Ulster,[372] the Annals of Inisfallen,[373] and probably by a chronological notice in the Historia Brittonum.[374]

But though these data are decisive, the vulgar date 493 has become so generally current that it may not be amiss to point to one or two further considerations which make against it; especially as it is possible to dissociate it from the tradition that Patrick died at an age which is, to use a moderate expression, unusual—120, by supposing that he was born in the first years of the fifth century, was ordained bishop at the age of 30, and lived to the age of 90. This view would involve a forced explanation of the dates (see below) supplied by the Confession. It is to be observed (1) that the Annals and older sources do not furnish a single notice of any event in Patrick’s life between 461 and 493; these thirty-two years are a blank. (2) Negative evidence is also furnished by the oldest Life of St. Brigit (by Cogitosus), which does not mention Patrick, or make any attempt to bring Brigit into connexion with him (as the latter Lives do, on the ground of the supposed date of his death in 493). Further (3), Benignus, Patrick’s successor at Armagh, died in 467 (Ann. Ult. sub a.; Annals in the Book of Leinster, f. 12, vᵒ A, see my extract in English Historical Review, xvii. pp. 700-1, 1902); and it will be allowed to be supremely improbable that Patrick should have resigned his bishopric when he was 60 years old or thereabouts, and survived his resignation 30 years. The question of the origin of the date 493, and of the two fabulous ages of Patrick (120 and 132) are treated in .

Our other data depend upon the Confession. He had committed some fault when he was about 15 years old;[375] he had confessed it to a friend before he was ordained deacon;[376] and through the treachery of his friend[377] it was afterwards urged against him. These machinations against him occurred post annos triginta,[378] which has been generally interpreted to mean 30 years after the commission of the fault.[379] It is also generally assumed that the hostile machinations of which Patrick complains occurred in connexion with his consecration as bishop. I will show that the first of these two assumptions is not certain, and that the second is erroneous; but, as they are usually accepted, I may first explain the chronological reconstruction which could be based on them. If Patrick’s fault committed at the age of 15 was urged against him 30 years later when he was consecrated bishop in A.D. 432, we at once get his age in that year as 45, and the date of his birth as A.D. 387, and the date of his captivity (= 387 + 16/17) as A.D. 403/4. This would follow, if we took the two numbers mentioned by Patrick as strictly precise. But it is to be observed that he gives the number 15 as approximate (nescio, Deus scit, si habebam tunc annos quindecim), and that 30 may be a round number. When he says that he does not think he was more than 15 when the delinquency was committed, we may presume that he was at least 15; on the other hand, we may take it that the number 30 is more likely to be slightly an over-statement than an under-statement. We should have, therefore, to consider it quite possible that the two numbers taken together might represent a period of somewhat less than 45 years—43 or 44; and it would not be safe to draw a more precise inference than that the birth date fell between 387 and 390, and the captivity between 403/4 and 406/7.