 The "Anglo-Saxon Chronicle" records that in 1003 Wilton was sacked by Vikings and the inhabitants retreated to Salisbury, and it is likely that the change of type coincided with this event.However, there are a number of difficulties with reconstructing such a fixed framework.Not all types are as well represented in the surviving material, and it is clear that this is not always simply a result of a few large hoards distorting our view.