We don’t really know the scale of Viking settlements in Southern England. It’s hard to identify buildings as specifically Scandinavian, and although in the North of England there is genetic evidence for a Norwegian legacy, the settlers in the South were mainly Danish, and too close in origin to the Anglo-Saxons for a clear distinction to be easily made.
Finds of Scandinavian oval brooches, swords and other items have confirmed that Vikings definitely came to England. The distribution of the finds suggests however that only first or second generation settlers maintained the Scandinavian style of dress. It seems that there were not repeated waves of settlers as in Iceland to build up a Norse community: Iceland was unoccupied and land was there for the taking, unlike England which was already fully occupied. Instead, single settlement events seem to have occurred and then fairly soon afterwards the settlers disappeared from our sight. Possible explanations include:
The Hólmbyggja settled on Osea Island in Essex around the year 880, when Guthrum allocated land in East Anglia to his followers. Again, we don’t know whether there was major population replacement, minor settlement or merely a takeover of the aristocracy – it may also have varied from region to region. The story of the Hólmbyggja assumes that relatively small numbers of Viking warriors and their families settled in lands which were inhabited by the Anglo-Saxons but temporarily under Danish rule. Most of the neighbours would have been English, and there would have been pressure to learn the language and adopt Christianity: according to Icelandic sagas, when a Christian king defeated pagans, they could buy their freedom by being baptised.
There was no room for further immigrants and the descendents of the original settlers were more concerned with establishing a position within English society. It’s likely that by 920, Essex was under English rule again, at which time some of the original settlers may still have been alive. Certainly English rule was fully re-established by the time of the Battle of Maldon in 991, which was part of the fresh wave of Viking invasions.
On St Brice’s Day 1002, Aethelred ordered that all the Danes living in England be killed. It’s not known whether this order applied to settlers of long standing within the Danelaw, or only to the newcomers who were extorting Danegeld and terrorising the coasts. It was not a good time to be seen as a Dane, and if the Hólmbyggja had not been sufficiently Anglicised they may have fallen victims.
Osea Island is close to Northey Island, the site of the Battle of Maldon. According to the Domesday Book, in 1066 Osea Island was owned by Thorbert, and Northey Island by Thorbern. These names are Anglicised versions of Old Norse names, and it’s possible that these men were descendants of ninth century settlers.