The depiction of Spain and Spaniards (or, by extension, all Hispanics and their countries of origin) as bloodthirsty and cruel, greedy and fanatical.
Wiktionary
Origin of Black-legend
The term was calqued from Spanish, where it was coined as Leyenda Negra by Julián Juderías in his 1914 book La leyenda negra y la verdad histórica (The Black Legend and Historical Truth).
