From Wikipedia

The Fith Age of Britain

1066-1350 AD

The Anglo-Normans were mainly the descendants of the Normans who ruled England following the Norman conquest by William of Normandy in 1066. A small number of Normans were already settled in England prior to the conquest. Following the Battle of Hastings, the invading Normans and their descendants formed a distinct population in Britain, as Normans controlled all of England, parts of Wales (the Cambro-Normans) and, after 1169, vast swaths of Ireland (the Hiberno-Normans). Over time their language evolved from the continental Old Norman to the distinct Anglo-Norman language (an Old French dialect).