The European practice of conceptualizing their enemies so that they could dispose of them in ways that were not in accord with their own Christian principles is well documented. In the Americas, this began with Columbus's designation of certain Indians as man-eaters and was continued by those Spanish who also wished to enslave the natives or eliminate them altogether. The word “cannibal” was invented to describe such people, and the Spanish were legally free to treat cannibals in ways that were forbidden to them in their relations with other people. By the late fifteenth century the word cannibal had assumed a place in the languages of Europe as the latest concept by which Europeans sought to categorize the “other.” As David Gordon White has shown, by the time the Spanish discovered America, barbarians were an established component of European mythology, history and theology as well as popular thought, and the categories Europeans employed to describe outsiders date as far back as the Greeks and the Egyptians before them. Therefore, it is not surprising that when they reached Mexico the Spanish easily adopted a word from Nahuatl to describe the Indian peoples of the north whom they believed to be barbarians. This word, chichimeca, which both designated and defined in a very particular way the native peoples of the north Mexican frontier, assumed in Spanish the credibility of longstanding native use, although as we shall see, this was not entirely justified.
Gradie, C.M. (1994). Discovering the Chichimecas. The Americas, 51(1), 67-88. doi: 10.2307/1008356