The term Midieaval Britain ususally refers to the period from the withdrawl of the Roman legions under Constantine, until the 16th century reformation in Scotland.

A series on invations, primarily by Germanic tribes, took place in the vacuum left by the departing Roman-led armies. Following the arrival of Anglo-Saxon troops led by the legendary Hengest and Horsa, the Celtic powers were conquered by Jutes, Angles and Saxons from the area of present-day Denmark, as well as Norwegians who settled in Scotland and Cumbria.

Earlier expeditions, notably by Julius Caesar, had not formally absorbed Britain into the empire and had been of variable success, though military remains from a pre-44 period suggest considerable Roman influence before the invasion took place.

Major historical developments included the continuing establishment of Christianity among the peoples of Britain, spreading the traditions that were inherent from the Roman times, and the rapid decline of civilization.

The period from secession of Roman government in Britain until the Norman conquest can trully be called the "dark ages" of Britain, as not a single written word or piece of artwork from that period has been found.

William duke of Normandy ("William the Conqueror"), landed at Hastings, defeated the armies of king Harold Godwinson of the Saxons, in the famous battle of Hastings, October 14th, 1066, killed Harold and became king.