Already before the unification of England by the Wessex kingdom, there had been Viking attacks in Britain. The first confirmed raid took place in the late 8th century, though there had certainly been others.
Vikings would make regular raids on England during most of the 9th and 10th centuries. There were also several war campaigns against the kingdom of Denmark, which would keep English kings constantly on their guard. At some point, England would even formally be under Danish rule. England was annexed to the North Sea Empire, with Denmark and Norway.
England under Norman rule
Another transformation came with William the Conqueror and the Norman Conquest of Britain, which brought England to Normand rule.
The Norman period of English history is important because it fundamentally changed the social order of the nation. The structure of aristocracy and political elite was completely reshuffled, as was the church.
The Normans also influence the culture and the language. Norman-French became the language of the aristocracy and administration, and more European influences emerged.
The cultural and social influences of the Norman period can still be perceived in modern English society. This period is also visible today in a very concrete manner, as the Normans built a large number of castles and monuments.
Middle Ages in England
The Norman rule also set the ground for the Middle Ages in England, particularly in terms of the feudal political order and foreign relations. It was a defining moment for the eras to come.
Much of this period would come to be defined by internal turmoil and civil wars, as well as extensive foreign conflicts, including the Crusades and the Hundred Years War with France.
Norman period also defined England’s relations to the rest of Europe, bringing it closer to continental Europe and to an extent breaking old ties with Scandinavia.