Legal English the history of the development of English as a legal language. In prehistoric Britain, traditional common law was discussed in the vernacular (see Celtic law). The legal language and legal tradition changed with waves of conquerors over the following centuries. Roman Britain (after the conquest beginning in AD 43) followed Roman legal tradition, and its legal language was Latin. Following the Roman departure from Britain circa 410 and the Anglo-Saxon invasion of Britain, the dominant tradition was instead Anglo-Saxon law, which was discussed in the Germanic vernacular (Anglo-Saxon, Old English), and written in Old English since circa 600, beginning with
English poetry language. The new aristocracy spoke predominantly Norman, and this became the standard language of courts, parliament, and polite society. As the invaders integrated, their language and literature mingled with that of the natives: the Oïl dialect of the upper classes became Anglo-Norman, and Anglo-Saxon underwent a gradual transition into Middle English. While Anglo-Norman or Latin was preferred for high culture, English literature by no means died out, and a number of important works illustrate the development of the language. Around the turn of the 13th century, Layamon wrote his "Brut", based on Wace's 12th century Anglo-Norman epic of the same