black legend

Short definition from Wiktionary

Noun

1. 1
   Historiographical phenomenon in which a sustained trend in historical writing of biased reporting and introduction of fabricated, exaggerated and/or decontextualized facts is directed against particular persons, nations or institutions with the intention of creating a distorted and uniquely inhuman image of them.

Proper noun

1. 1
   Alternative letter-case form of Black Legend.
2. 2
   The depiction of Spain and Spaniards (or, by extension, all Hispanics and their countries of origin) as bloodthirsty and cruel, greedy and fanatical, especially concerning the colonial period from the sixteenth to the eighteenth century.