Changes

By 865, the Danes and Norse had seen the British Isles as a region to settle rather than simply raid (Figure 1). 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, where a more stable economy could be established for them. The British Isles, fed by the warmer waters from the Gulf stream, was were 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.<ref>For more on the background on the conflict between the Vikings and Anglo-Saxons, see: Baillie, Benjamin James. 2015. The Great Heathen Army: Ivar "the Boneless" and the Viking invasion of Britain. Benjamin James Baillie.</ref>

Although Alfred faced a devastating defeat and was forced to seek refuge in the swamps of Somerset, he was able to reorganize himself , in part by acting as a rallying cry against the polytheistic Danes, 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. This bought time for Wessex to become even more powerful and develop better army strength to fight the remaining Danes and Norse in England. While the invasions by Danes and Norse likely seemed to be a threat to Anglo-Saxon England, it also 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.<ref>For more on why Alfred the Great was able to triumph over the Vikings, see: Dougherty, M.J. (2014) <i>Vikings: a dark history of the Norse people.</i> New Holland Publishers.</ref>

As the Danes and Norsemen remained largely fragmented, Alfred went about unifying his kingdom and building a stronger base of support among Anglo-Saxon populations. First, he appealed to most of them using his religion. This also helped to bring some Britons to his cause, who likely saw Christianity as a way to unite against the invaderseven though they often fought the Angles and Saxons. Second, Alfred married his daughter, Æthelflæd, to Mercia, which helped to eventually bring that former Anglo-Saxon kingdom into Wessex's control. In fact, after Æthelflæd's husband, Æthelred, died, she was able to rule Mercia and effectively bring it into the control of Wessex. Mercia was once the most powerful of the Anglo-Saxon kingdoms. With Wessex's control of Mercia, it was able to use it as a base to then re-conquer East Anglia in the reign of Edward, Alfred's son, and then Northumbria, during the reign of Æthelstan.In effect, the control of Mercia was critical to the eventual unification of all of England, as it brought the two more populated regions under united control.<ref>For more on the process of unification for England, see: Stafford, P. (1989) <i>Unification and conquest: a political and social history of England in the tenth and eleventh centuries.</i> London ; New York : New York, NY, E. Arnold ; Distributed in the USA by Routledge, Chapman, and Hall.</ref>