Analysis of information sources in references of the Wikipedia article "Geoffrey Chaucer" in English language version.
The extraordinary dominance of English now as a world language has made it hard to appreciate that its status in the medieval period was very low. Not only was English just one of three languages used in England before the 15th century, it was not the major one. Although it was, of course, the most widely used spoken language, English fell far short of Latin and French as a written language. [Chaucer's] decision to write exclusively in English was indeed unusual [...] He made English successful because he made it urban and international.