The term used by historians of the English language to denote a stage of its development intermediate between Old English (or ‘Anglo‐Saxon’) and modern English. In this historical scheme, Middle English is the language spoken and written between about 1100 and about 1500. In this period, English is influenced in many aspects of its vocabulary by a new French‐speaking ruling class, and by a clergy that wrote mainly in Latin. Middle English grammar and syntax are clearly those inherited from the Germanic basis of Old English, although now shedding its inflections and distinctions of gender. Strong differentiation appears among dialects, of which the East Midlands variety proved to be the most important basis of modern English. The period is commonly subdivided into Early Middle English (approximately 1100–1300) and Later Middle English (1300–1500). In its literary manifestations, Early Middle English is the language of The Owl and the Nightingale, while Later Middle English is that of Langland, Chaucer, and Malory.
http://www.georgetown.edu/labyrinth Labyrinth, an extensive medieval studies resource.