When William the Conqueror led the Norman conquest of England in 1066, he, his nobles, and many of his followers from Normandy, but also those from northern and western France, spoke a range of langues d'oïl (northern varieties of Gallo-Romance). One of these was Old Norman, also known as "Old Northern French". Other followers spoke varieties of the Picard language or western French. This amalgam developed into the unique insular dialect now known as Anglo-Norman French, which was commonly used for literary and eventually administrative purposes from the 12th until the 15th century. It is difficult to know much about what was actually spoken, as what is known about the dialect is restricted to what was written, but it is clear that Anglo-Norman was, to a large extent, the spoken language of the higher social strata in medieval England.
It was spoken in the law courts, schools, and universities and, in due course, in at least some sections of the gentry and the growing bourgeoisie. Private and commercial correspondence was carried out in Anglo-Norman or Anglo-French from the 13th to the 15th century though its spelling forms were often displaced by continental spellings. Social classes other than the nobility became keen to learn French: manuscripts containing materials for instructing non-native speakers still exist, dating mostly from the late 14th century onwards.
Although Anglo-Norman and Anglo-French were eventually eclipsed by modern English, they had been used widely enough to influence English vocabulary permanently. Thus, many original Germanic words, cognates of which can still be found in Nordic, German, and Dutch, have been lost or, as more often occurs, exist alongside synonyms of Anglo-Norman French origin. Grammatically, Anglo-Norman had little lasting impact on English although it is still evident in official and legal terms where the ordinary sequence of noun and adjective is reversed, for example attorney general: the spelling is English but the word order (noun then adjective) is French. Other such examples are heir apparent, court martial, and body politic.
The Royal coat of arms of the United Kingdom still features in French the mottos of both the British Monarch, Dieu et mon droit ("God and my right") and the Order of the Garter, Honi soit qui mal y pense ("Shamed be he who thinks evil of it").