The last Roman legions withdrew in AD 410 and with them went the system of Roman administration and links to a long distance market economy. The period is known as the Dark Ages because of the lack of historical and archaeological evidence caused by this collapse of civic authority. Coins were no longer struck and pottery was no longer imported. Pollen evidence from Swaledale shows the regrowth of woodland but this is likely to be a reflection of farmers not having to grow a taxable surplus any more rather than a major depopulation of the area.
In the Yorkshire Dales it seems more than likely that life went on much as normal. The native population seemed to have been little touched by the material trappings of romanised life and so probably didn’t miss them when they were gone. People probably went on farming and they certainly went on caring for their dead as shown by the evidence of the female burial found near Kettlewell in 2000 and radiocarbon dated to the 7th century AD. She had no grave goods with her but someone cared enough to bury her, possibly originally under an earth mound.
The political vacuum was eventually filled by a number of powerful chiefdoms that grew up in the late fourth and early fifth century. The bulk of the Yorkshire Dales seems to have lain on the edge of the main ones such as Elmet and Craven. The area was probably controlled by small independent tribal kings or chiefs of whom no record survives.
It wasn’t long before these leaders were fighting for their political existence as the first waves of Anglian migrants arrived from what is now Denmark. We see archaeological evidence for the turmoil caused by these settlers in Swaledale. A series of large dykes were built near Grinton apparently to mark the boundary between native land to the west and Anglian territory to the east. The dykes are difficult to date and may have been built at any time between the fifth and early seventh centuries. Another impressive example of a boundary earthwork is Tor Dyke on the watershed between Wharfedale and Coverdale. This is now believed to be the north-eastern boundary of the native kingdom of Craven. It faces towards Craven and so it seems likely to have been built by Anglians to resist pressure on their territory.