The period of Norman Britain, spanning from approximately 1066 to 1154, represents a transformative era in English history triggered by the Norman Conquest. Following the decisive victory at the Battle of Hastings, the arrival of the Normans fundamentally altered the structure of society, governance, and the cultural landscape of the kingdom. This transition saw the displacement of the Anglo-Saxon aristocracy and the introduction of a new feudal system that redefined landholding and social hierarchy across the country.

Central to the consolidation of Norman power was an ambitious programme of castle-building, which served as a physical manifestation of their authority and a means of controlling the local population. This era also saw the creation of the Domesday Book in 1086, an unprecedented administrative survey that recorded the landholdings and resources of the realm to facilitate efficient taxation and governance. These developments were accompanied by a significant shift in elite culture, as Norman French became the language of the ruling class and continental architectural styles, such as the Romanesque, began to dominate the construction of cathedrals and fortifications.

The influence of the Norman monarchs also reoriented England towards continental Europe, strengthening political and religious ties with France and the wider Latin West. This period of intense change laid the foundations for the medieval state, leaving an enduring legacy on the legal, social, and architectural fabric of Britain. The key developments of this era include:

• The establishment of a new feudal system and landholding structure.
• The widespread construction of motte-and-bailey and stone castles.
• The commissioning of the Domesday survey to document the nation's wealth.
• The introduction of Norman French as the language of the elite.
• The strengthening of political and cultural links with continental Europe.