Medieval French literature is, for the purpose of this article, Medieval literature written in Oïl languages (particularly Old French and early Middle French) during the period from the eleventh century to the end of the fifteenth century. The material and cultural conditions in France and associated territories around the year 1100 unleashed what the scholar Charles Homer Haskins termed the "Renaissance of the 12th century" and, for over the next hundred years, writers, "jongleurs", "clercs" and poets produced a profusion of remarkable creative works in all genres. Although the dynastic struggles of the Hundred Years' War and the Black Death pandemic of the fourteenth century in many ways curtailed this creative production, the fifteenth century laid the groundwork for the French Renaissance. Language Up to roughly 1340, the Romance languages spoken in the Middle Ages in the northern half of what is today France are collectively known as "ancien français" ("Old French") or "langues d'oïl" (languages where one says "oïl" to mean "yes"); following the Germanic invasions of France in the fifth century, these Northern dialects had developed distinctly different phonetic and syntactical structures from the languages spoken in southern France. The language in southern France is known as "langue d'oc" or the Occitan language family (a language where one says "oc" to mean "yes"), also known under the name of one of its dialects, the Provençal language). The Western peninsula of Brittany spoke Breton, a Celtic language. Catalan was spoken in the South, and Germanic languages and Franco-Provençal were spoken in the East. The various dialects of Old French developed into what are recognised as regional languages today. Languages which developed from dialects of Old French include Bourguignon, Champenois, Franc-Comtois, Francien (theoretical), Gallo, Lorrain, Norman, Anglo-Norman (spoken in England after the Norman Conquest of 1066), Picard, Poitevin, Saintongeais and Walloon. From 1340 to the beginning of the seventeenth century, a generalized French language became clearly distinguished from the other competing Oïl languages. This is referred to as Middle French ("moyen français"). The vast majority of literary production in Old French is in verse; the development of prose as a literary form was a late phenomenon (in the late Middle Ages, many of the romances and epics were converted into prose versions). The French language does not have a significant stress accent (like English) or long and short syllables (like Latin). This means that the French metric line is not