This isn't really about raids, but I couldn't find a thread that might cover Viking settlements in England:

The secrets of Norwich's past are being unearthed as part of archaeological digs in the north of the city - where city walls which date back to the Vikings have been discovered.

Archaeologists have discovered remains from the city's old walls, dating back from the 10th century, as part of excavation work being carried out in the Botolph Street area, near Anglia Square. The work, which started two weeks ago, is being carried out in advance of a planning application to assess what lies under the ground and is expected to continue until early November.

It is believed the discovery of the ancient city walls reveals Norwich's historic links with the Vikings.

The full report is in the Norwich Evening News