What is "middle french"

Middle French is a historical division of the French language that covers the period from the fourteenth to the early seventeenth centuries. It is a period of transition during which:

• the French language becomes clearly distinguished from the other competing Oïl languages, which are sometimes subsumed within the concept of Old French (ancien français)
• the French language is imposed as the official language of the kingdom of France in place of Latin and other Oïl and Occitan languages
• the literary development of French prepares the vocabulary and grammar for the Classical French (français classique) spoken in the 17th and 18th centuries.