The fifth-century events mentioned by Nennius in Passage 66 (trans. John Morris, British History and The Welsh Annals) are taken as being accurate. Many have argued that its elaborate dating is glossed in or false. In either case, it points to an alternative dating for the reign of Vortigern than what is offered by Bede (trans. Judith McClure and Roger Collins, Bede – The Ecclesiastical History of the English People – The Greater Chronicle – Bede’s Letter to Egbert). Through the removal of Aëtius time-stamping in Gildas, the sources fall in sync. Passages 43 to 46 by Nennius and sections [vi.13], [vi.14], [vi.15] and [vi.16] by Geoffrey of Monmouth in The History of the King of Britain fill out this fifth-century time line. Bishop Germanus’ visit in 429 forms the keystone in synchronizing the three sources.
Both Nennius and Geoffrey tell of four battles that Vortimer waged against the Saxons. Geoffrey elaborates on other events in section [vi.14]. Soon after the fourth victory, Vortimer restored the churches as Bishop Germanus requested.
This gives the impression that Bishop Germanus was still in Britain after the four battles. Due to the timing and their general descriptions, it seems possible that the battle Bishop Germanus had against the Saxons and the Picts on Easter Sunday [April 8th] was one of the four battles Vortimer had against the Saxons.
In comparing the details described in sections XVII and XVIII of the Life of St. Germanus, Bishop of Auxerre (trans. F. R. Hoare, The Western Fathers) to the ones listed in Nennius’ passage 44, it seems that the Alleluia victory would have been the battle on the river Darenth or at the ford called Episford. This conjecture comes from the following line by Constantius of Lyons. Many [the enemy – Saxons and Picts] threw themselves into the river which they had just crossed at their ease, and were drowned in it. Other information used to form this conjecture was gathered from Peter Clayton’s A Companion to Roman Britain. He tells of the Lullingstone villa that sat on the Darent River not far from the village called Eynsford. The villa burned down early in the fifth century. Though lacking definitive archeological evidence and not suggested by Clayton, the villa’s fiery end could be attributed to Saxon rage.
According to Geoffrey of Monmouth, Vortimer laid siege to Thanet in his fourth and final battle against the Saxons. During a parley between the opposing sides, the Saxons sailed off to Germany in their longships. Vortimer was poisoned shortly after ordering the churches to be restored in section [vi.14].
John Haywood cites in his book, Dark Age Naval Power: (with a small professional sailing crew) In fair weather, each voyage across the North Sea would have been measured in days rather than weeks and the risks would have been slight. In terms of traveling time the 300-mile voyage between Jutland and the Thames estuary would have been no longer than a 60 mile-long journey overland.
The Saxons returned. During a meeting set up by Vortigern, Hengist and his men massacred many British nobles on the first of May, the date agreed upon in section [vi.15] and described in section [vi.16] of The History of the Kings of Britain.
It seems possible that one of the four battles of Vortimer, his death and the British massacre occurred in a rapid succession between Easter Sunday [April 8th] and May 1, 429.