Changes

By 865, the Danes and Norse had seen the British Isles as a region to settle rather than simply raid. At that point, conditions in Scandinavia may have forced many populations out of the region because it became difficult to farm. This likely encouraged many Danes to take to raiding and then later into settling new areas. The British Isles, fed by the warmer waters from the Gulf stream, was attractive and fertile land. After landing in 865, eventually the Danes had defeated three of the four kingdoms of England, including Northumbria, Mercia, and East Anglia, with only Wessex having survived this onslaught. The conflict with Wessex occupied much of the late 860s and early 870s. Alfred, later known as Alfred the Great, took up the throne of Wessex and confronted the Danes.

Although Alfred faced a devastating defeat and was forced to seek refuge in the swamps of Somerset, he was able to reorganize himself and won the crucial battle of Edington. This helped to re-establish Wessex and new boundaries where areas north of Wessex and to the east became Danelaw, or regions where the Danes ruled. Alfred created a series of fortified towns or forts, known as burhs, that made the conquest difficult for Danes or Norse attackers, as they had not developed effective siege warfare tactics. While the invasions by Danes and Norse likely seemed to be a threat to Anglo-Saxon England, it effectively gave Alfred a chance to foster the idea of a unified English speaking kingdom, which was also Christian. This helped it stand as a contrast to the Dane and Norse regions that were polytheistic. Furthermore, Danelaw lacked very strong central governments, where the rulers often had little real power and local warlords were able to do as they please.