The medieval period in Britain traditionally begins with the Norman conquest in 1066. The conquest began with William of Normandy’s defeat of Harold Godwinson at Battle, near Hastings.
The initial conquest involved only a relatively small force of Norman soldiers, but after Harold’s defeat William was handed the crown and accepted as King by the majority of the surviving nobility. Though resistance continued for a while, the Normans’ great success was in their ability to take over existing Saxon systems of government and in largely leaving the administrative structure of the country intact, while evicting large numbers of native landowners. The feudal system they brought with them further defined the existing social structure and this may also have helped enforce their power.
Most notable in the archaeology of the Norman period is the increase in stonework; some people refer to a "Great Rebuilding" early in the Norman period where many Saxon timber structures were replaced with stone. This may be a simplified view, and it is certain that timber continued to be used for domestic buildings, especially in Essex, well into the later medieval period.