407, and in the later form of the tradition they are certainly identified.[162] Bede tells us that after the arrival of the Saxons in 449 they united with the Picts, whom they had driven back, and attacked the Britons, when they were defeated in the Allelujatic victory; but Constantius, from whom this event is taken, and who was nearly a contemporary writer, dates this event in the year 429, thus showing the Saxons in combination with the Picts twenty years before the date assigned by Bede for the arrival of the former; and here again the true date of this event is in harmony with the third date assigned in Nennius for the arrival of the Saxons, viz., the year 428. Finally, we have the testimony of Prosper Aquitanus, whose chronicle was compiled in the year 455, that in 441 the British provinces had already been reduced under the power of the Saxons.[163] Five years after this the letter to Aetius was written, and it follows that the Barbarians, against whom it made that despairing cry for assistance, were the Saxons, and to them the expressions quoted from the letter are much more applicable than to the Picts and Scots.[164] The misplacing of this document in Gildas’s narrative has given rise to the false chronology which has been attached to it, and we are warranted in concluding that the settlement of the Saxons on the south-eastern shore had commenced as early as the year 374, and that Britain was considered as under subjection to them at least eight years before the date in which Bede places their first arrival. Gildas records no events between the victory, which he attributes to the leader of the Roman party, Ambrosius Aurelianus, and the siege of Mount Badon in 516. Nennius, who connects Ambrosius with the Roman power, and alludes to a discord between him and Guitolin, of which he gives no particulars, but which he places in the year 437, fills up this interval with the exploits of Arthur. [Sidenote: War with Octa and Ebissa’s colony.]