Why the Middle Ages are called the Dark Ages

de bene esse: literally, of well-being, morally acceptable but subject to future validation or exception

http://www.medievalists.net/2014/02/04/why-the-middle-ages-are-called-the-dark-ages/

Why the Middle Ages are called the Dark Ages - Medievalists.net

medievalists.net

How did the term 'Dark Ages' become synonymous with the Middle Ages, and why do we still refer to it like that?