But the central paradox of the Anglo- Saxon migration stays firm within the unavailability of substantial evidences. Till date there are considerable debates as to the extent of Anglo-Saxon migration from the fourth to the sixth centuries. This because we are unable to finds enough evidences regarding this migration and whatever is available proves to be unworthy as a sustainable source to prove within the academic consensus. As a result no single model of Anglo- Saxon migration can be taken into account academically.
The initial interpretation of the Anglo- Saxon migration during the fourth to the sixth centuries suggested that the Anglo-Saxon tribes arrived in Britain in large numbers and settled down instantly. This process was instigated by mass genocide and effective displacement of the local communities of the 'Britons' (as depicted in Latin Texts) from the eastern and southern parts of the island. It is also believed that a minority of the Romano-British fled to Brittany and Galicia in northern Spain.
Probably during the early sixth-century or late fifth century monk Gildas narrated the defeat of the British in the hand of the English and stated that this defeat was the result of a punishment from God in his writing De Excidio Britanniae. (Gildas, 77) A similar narrative appeared in Bede's Historia Ecclesiastica gentis Anglorum, written in the early eighth century, which drew heavily on Gildas. This era of cataclysm was focussed by later Anglo-Saxon and British (Welsh) documents on the basic differences between the English and the Welsh. But many historians doubt the story - believing many or most Britons survived - but evidence to back up their account has always been hard to find. This is because the 7th century laws of King Ine of Wessex contain regulations for Britons, in a way that implies their close co-existence with Anglo-Saxons, probably as slaves or serfs.
This interpretation could be stretched and could be used as a palpable support within the strata of linguistic and place-name evidence. Linguistically, few p-Celtic words find their way into old English, though some have argued for greater input than was previously thought. The apparent rarity of obviously Brythonic place-names has been used to downplay continuity, but such names may be difficult to identify rather than absent.
It remains controversial as to how much these periods coincided with substantial immigration from continental Europe, even for those that occurred most recently. Examining genetic data for evidence of male immigration at particular times into Central England and North Wales 12 biallelic polymorphisms and six microsatellite markers to define high-resolution Y chromosome haplotypes in a sample of 313 males from seven towns located along an east-west transect from East Anglia to North Wales reveals that the Central English towns were genetically very similar, whereas the two North Welsh towns differed significantly both from each other and from the Central English towns. When data was compared with an additional 177 samples collected in Friesland and Norway, it was found that the Central